1870, July 21 - First day of service on the Ottawa City Passenger Railway which received its charter on August 15, 1866.  A short section of rail was laid on 19 August 1867 in New Edinburgh, presumably to keep the charter alive.

1891, July 29 - Official opening of the Ottawa Electric Street Railway.

1891, November 1 - trolley mail cars start operating in Ottawa.  Full service commences 9 Nov 1893 to convey Her Majsety's mails from the central post office to the railway stations.

1892, August 6 - the Ann Street line is opened.

1893, June 23 - the Rockcliffe line is opened between New Edinburgh and Rockcliffe.

1893, July 26 - first electric streetcar operated on Sparks Street.

1893, July 29 - Order in Council passed authorizing a contract between the Post Office department and the OER for the conveyance of mails between the city post office and the railway stations.  The OER agreed to construct a siding from Sparks Street to the post office door and three special mail cars were to be built so that the mail bags could be slid without handling from the electric cars into the post office or the railway mail cars.

1893, August 3 - Sparks Street line electrified throughout.  All car routes in the city are routed over Sparks Street.

1893, August 4 - First electric cars run on Sussex Street.

1893, August 13 - Ottawa Electric Railway is formed through the amalgamation of the Ottawa City Passenger Railway and the Ottawa Electric Street Railway.  They also applied for permission to lay a double track on Bank Steet between Sparks and Albert Steets to connect the two railways.

1893, November 1 - Electric mail cars begin operating to Union Depot, the CAR depot and to the Empress Landing at the Queens Wharf as well as to points nearest to places such as Cummings Bridge and other suburban post offices.  These cars are rebuilt from former passenger cars and were vestibuled at each end.  They were run between the depots and the post office without stopping and were equipped with a large gong which had a louder tone than those on the passenger cars to warn people of their approach when at least two or three blocks away from any street crossing.  The mail cars were lighter than the ordinary cars and ran at higher speeds.

1893, November 3 - The electric car rails between Dufferin Bridge and Metcalfe Street on Wellington Street are taken up, the route having been abandoned.

1894, May 3 - Electric car service is opened to Rockcliffe Park which was formally opened on this day.  Double tracking of the Rockcliffe Extension was completed on April 20, 1894.  In developing Rockcliffe park, the OER installs the first electric merry-go-round in the world.

1896, June 23 - Hull Electric Railway takes delivery of the first electric locomotive built in Canada.  It was built by the Canadian General Electric Company.

1896, June 24 - Hull Electric Railway is opened, a trial run between Hull and Aylmer was made on 19 June 1896.  

1897, January 18 - The Ottawa Citizen reports "The finishing touch to the Ottawa Electric Railway Company's massive iron bridge between Ottawa and Hull was  made on Saturday, when the Ottawa cars which have been running as far as the Eddy Company's match factory, were able to proceed the 200 additional feet between that point and the company's waiting room in Hull. The Hull and Alymer Company's cars now run down side by side with the Ottawa cars thus making a very easy and convenient transfer. The waiting room fitted up by the Ottawa company in the stone building formerly used by the Eddy Company is a model of neatness and comfort. It is sheeted throughout with ash and is lighted and heated by electricity. The Ottawa company has certainly left nothing undone to fully provide for the comfort of its passengers and those who go over the Hull and Alymer lines. The latter may now reach all parts of Ottawa by stepping from one car to another. The fare from Hull to all parts of Ottawa is the same as between points in Ottawa itself.

1897, 16 May - Hull Electric opens its new double tracked line between Hull and Aylmer, including a bridge over the Canadian Pacific Railway and extends from Aylmer to a new park (One Tree Point, later named Victoria Park) on Lake Deschene.

1898 - The cars of the Hull Electric company are equipped with headlights which had five lamps of 16 candle power each, placed together before a strong reflector.  This, together with altered gearing, allowed running speed to be increased to 40 mph.

1899, January 9 - Hull Electric purchases, for $100,000, the Canadian Pacific line between Aylmer and the main line at Hull.  Before this the Hull Electric had used the line under lease.

1899, July 23 - Sunday service is inaugurated on the Ottawa Electric Railway.  This required federal legislation, a repeal of part of the Company's provincial legislation as well as a City by-law.  The company donated $400 to the Associated Charities of the City out of the proceeds of the first Sunday's traffic.

1900, April 26-27 - the disastrous Hull-Ottawa fire destroys the Ottawa Electric powerhouse no. 1 at the Chaudiere Falls.  However, the company had just installed a back up 2,000 h.p. generator at the same location in a fireproof building.  Only the roof of the back up building was destroyed and service was interrupted only for 3 - 4 hours being restored the evening of the day of the fire.

1900, May 21 - First regular streetcar to Britannia.  The first trial run had taken place on December 18, 1899.

1900, August 28 - the Ottawa Electric Railway opens a double track extension to the new Dominion Rifle Association rifle range. The Association agreed to supply rails, ties and free right of way for this two mile extension.  The line was opened in time for the annual matches of the DRA which commenced on August 28..

1900, November - Rockcliffe streetcar barn is opened.

1901, July 25 - regular service is inaugurated on the Hull Electric Railway over the Interprovincial Bridge between Ottawa and Aylmer, (cars had commenced crossing the bridge on July 13th).  At 8:20 the previous evening the first car left Ottawa following a ceremony presided over by Mayor Morris.  Motorman George McConnell was in charge of the car.  Regular service was inaugurated on the afternoon of July 25.  A twenty minute service was put on till noon and a fifteen minute service the rest of the day

1901, September 23 - during their visit to Ottawa the Duke and Duchess of Cornwall and York travel on special OER car named "Duchess of Cornwall and York".  The party left Rideau Hall at 10:30 and travelled, through large cheering crowds, along Sussex, Rideau, Sparks, Wellingtonand Queen Streets.  At Bridge Street and along Oregon Street a special track had been laid to the river's edge where the party transferred to cribs for travel down the Chaudiere slides.  The royal party later took the car from the Rockcliffe Pavilion to a demonstration of tree cutting. loading and unloading as well as dancing and other passtimes peculiar to the shantymen's way of life.

1902 - the Hull Electric Railway is purchased by Canadian Pacific.

1906, September 8 - car No. 253 is the first streetcar to pass through the new Bank Street subway inder the Grand Trunk Railway.

1908, May 24 - there is a collision between two cars on the Britannia line.  E.A. Bredenbury, a London, England, mining engineer, was injured in the accident and had a leg amputated.  He was awarded $30,000 damages on 12 January 1909.  This resulted in a stringent set of regulations not allowing passengers to ride the front platforms nor engage in conversation with motormen as well as the space intervals allowed between cars.

1908, July 8 - construction commences on the Belt Line in Hull.  Work was completed in 1909 from which time freight cars were switched between Hull Station and the Laurier Avenue sidings between midnight ond 05:30.

1908, late August - the Ottawa Electric Railway introduces its first two "Pay and you enter" cars.

1908, November 12 - regular service commences on the Ottawa Electric Railway's 1.8 mile extension to the Dominion Experimental Farm.

1908 - the Ottawa Electric Railway constructs a new car barn on the west side of Coburg Street with storage room for 48 single truck cars.  The building was expanded in 1912 by the addition of four tracks to the existing six, and giving accommodation for an additional thirty cars.

1909, October 19 - the Hull Electric power house at Deschenes is destroyed by fire.

1910, September - Hull Electric extends its line from the CPR station on Main Street along Brewery Street and along the Chelsea Road to the first tollgate.

1912, November 25 - operation of the Hull Electric through the turning tunnel under the Chateau Laurier is authorized.

1913 - Hull Electric opens a 0.75 mile long double track extension from Rivermead to the Jockey Club, at Connaught Park.

1919, July 1 - Public transport in Ottawa is closed down by a serious strike on the streetcar system.

1924, January 24 - A second franchise for streetcar operation is signed with the city. This signals a massive modernization program.

1924, May 17 - an agreement between the Ottawa Electric Railway and the Minister of Public Works allows the railway to lay double tracks between Nicholas and Elgin Streets over the Laurier Avenue Bridge.  Service comenced over the Laurier Avenue bridge on 15 September 1924.

1925, May - the Ottawa Electric Railway opens the Champagne car shops.

1925, September 8 - Hull Electric discontinues through service to Queen's Park.  After this time service was provided by a transfer car running between Aylmer and Queen's Park.

1927, April - the Canadian Pacific sells the Hull Electric Railway to the Canadian International Paper Co.

1927, June 23 - the Rockcliffe streetcar barn burns.  Forty streetcars are destroyed.  It was subsequently rebuilt.

1929, December 10 - service is discontinued on the Ottawa Electric Railway streetcar line from Carling Avenue to the Experimental Farm.

1932, Summer - Street car tracks are removed from the Laurier Avenue bridge.

1932, September 18 - Rockcliff streetcar barn burns for the second time.  Seven streetcars and six pieces of work equipment are burnt.  The building was demolished by the Federal District Commission in 1946.

1935, June 15 - Hull Electric Railway is authorized to abandon service between Notre Dame street, Aylmer and Queens Park, Que. This 2.03 mile line had been operated for some years during the summer only.  The last tram operated over this section on 2 September 1934.

1939, April 25 - The Elgin Street streetcar line is abandoned. This is the first major rail abandonment in the city. The last run on Elgin to/from the Clegg Loop occurred April 25, 1939 just after midnight.

1946,  January 21 - Hull Electric Railway is fined $50.00 for infringing a municipal by-law prohibiting the movement of freight on Hull city streets between midnight and 05:30.  Service to oil companies located at Laurier Avenue is suspended because the company is unable to provide freight service at other times without interference to passenger service which it provided under contract with the City of Hull.

1946,  January 31 - Freight service on the Hull Electric Railway Belt Line is reinstated between the CPR Hull Beemer station and the Laurier Avenue sidings.  The streetcars were replaced by buses between 20:00 and 22:45 during which time the Hull Electric was permitted to operate its freight service.

1946, March 29 - fire destroys the north end of the Interprovincial Bridge.  As of this date the Hull Electric Railway  ceased to operate into the Chateau Laurier, Ottawa and turned its cars at the intersection of Laurier Avenue and Youville Street near the north end of the Interprovncial Bridge in Hull.  Three Hull Electric trams were marooned on the Ottawa side

1946, December 12 - Hull Electric Railway is authorized to discontinue all operations except the section between Aylmer and near the Ottawa Electric Railway Company loop in Hull which was discontinued effective 1 April 1947.

1948, August 12 - Ottawa Electric Railway is transferred to the City of Ottawa.

1954, November 27 - car No. 918 makes the final streetcar run from Hull to Ottawa.

1959, May 1 - Last revenue run of the Britannia streetcar line at 03:25 when OTC car 831 eased into the Coburg barn. Formal closing ceremonies, with a parade of 17 vehicles, were held on May 2.

Ottawa Light Rail Transit

2000, October - work commences on upgrading the following lines in preparation for introduction of light rail operation:

Ellwood subdivision between mile 0.00 and mile 4.99
Prescott subdivision between mile 4.90 and mile 8.17

2000, November - work commences on rebuilding the bridge over Sawmill Creek.  Steel piles are driven to replace the wooden ones.

2000, November 24 - Canadian Transportation Agency issues a certificate of fitness to Capital Rail in Decision No. 745-R-2000 which will permit the construction and improvements of a line to operate commuter services in Ontario and Quebec on the two sections of line above as well as on the Walkley Line between the junction with the Ellwood subdivision and the Canadian Pacific locomotive shop in Walkley Yard.

2000, December - extensions to the CP Walkley shop are completed.  This includes:

- extension of both the loco and car shop with a tent to allow for the longer trains.
- connecting a storage track for the third train south of the shops to the east end approach track.
- security fencing around the site.

2001, January 8 - work starts on the stations at:

- Carling (widening of rock cuts and ditchwork, as well as elevator shaft).
- Greenboro (install pedestrian overbridge from Transitway Station to trackside).

2001, January 18 - The three Talent railcars arrive at Shed #48, at the Logistical Terminal, Port of Montreal, at 08:00 on the vessel "Federal Trader".

2001, February 4 - The Talent railcars arrive in Ottawa early morning, having been moved from Montreal by CN.  Ottawa Central RS-18u's 1838, 1842 and 1865 forwarded the equipment to the shop in Walkley Yard.

2001, April 12 - The Capital Railway comes into existence.  Owned by the City of Ottawa, it leases the CPR Ellwood subdivision and the North Prescott spur, 8.17 miles as well as part of Walkley Yard.

2001, October 15 - service commences between Greenboro and Bayview.

2002, January 1 - fare paying service commences.  Before this time passengers travelled free.

2003, June 7-22 - O Train service is suspended while necessary track upgrades, including the laying of new continuously welded rail, are carried out.

2003, August 31 - O Train service is improved by increasing frequency from three an hour to four an hour.  This is made possible by the higher speeds resulting from the June improvements.

2004, May 14 - the O Train makes a demonstration run to Fallowfield station to participate in a municipal/provincial/federal announcement on transit funding.

2004, September 24 - the O Train makes a demonstration run from Ottawa to Carp and return.  Carp is on the line built by the Ottawa, Arnprior and Parry Sound Railway.

2004, December 2 - the City of Ottawa agrees to purchase the Canadian Pacific corridor from, and including, the Prince of Wales bridge, through the Dows Lake Tunnel and along the Ellwood subdivision to Leitrim Road for O Train expansion.  The cost for this 13 km. stretch of line is $12.6.

2005, May 6 - City of Ottawa (Capital Rail) takes ownership of the following lines:

  Ellwood subdivision between mile 0.00 and mile 4.99 (Ottawa West)
  Prescott subdivision between mile 4.90 and mile 4.99 (Greenboro)
  Prescott subdivision between mile 4.99 and 8.17 (Leitrim Road).  This is excepted track for possible future expansion.
  Walkley Line between the junction with the Ellwood subdivision and Albion Road
  On this date the City leased the line east of Albion Road to the Walkley Repair Facility.

2006, January 24 - City of Ottawa (Capital Rail) takes ownership of the Prescott subdivision between mile 7.17 and mile 25.42 (Highway 416).  This is excepted track for possible future expansion.

2006, April 8 - the City of Ottawa announces that Siemens has been chosen to built the light rail line.

2006, August 31 - the Canadian Transportation Agency approves the construction of the LRT from the Mackenzie King Bridge to Woodroffe Avenue.

2008, December 10 - the O Train is shut down by a strike by the Amalgamated Transit Union.  Trains finally started running again on 2 February 2009.

2011, June 22 - the City of Ottawa approves the purchase of six new diesel train sets and the doubling of tracks in two areas to allow O Train service frequency to be reduced to every eight minutes.  

2011, September 15 - OC Transpo reaches an agreement with train supplier Alsthom to purchase six new Coradia Lint 41 trains that will begin O-Train service in early 2014.

2013, April 27 to September 2 - The OTrain is shut down to allow work to be carried out to improve line capacity.

2013, May 22 - works starts on the diversion of the transitway between Laurier and Campus to allow the construction of the eastern portal of the LRT tunnel. On June 23 buses started to use the new route with construction starting in July.

2013, June 20/21 - the 6 Alstom CORADIA LINT trainsets ran from Coteau to Ottawa under their own power.  

2013, September - blasting commences on the construction of the LRT tunnel at Lebreton.

2013, October 12 - O-Train service between Carleton and Bayview Stations is suspended on weekends until January 4 in order to allow Carleton University to complete the foundations of a new parking garage situated over the light rail tracks near Carleton Station.

2016, November 28 - An Alstom LRV tram makes its first trial journey on the main line from Belfast Road shops to  Cyrville station where it tied up overnight.

2017, November 30 - OC Transpo discontinues to sale of paper tickets which will be valid until April 30 2018.

2018, April 14 - One of the new Citadis Spirit vehicles for the Confederation line runs through the tunnel under downtown and reaches the western terminus at Tunneys Pasture.

2018, May 4 - A ceremony is held to celebrate the driving of the last "clip" on the Confederation line

2019, September 14 - the Confederation line is opened from Tunneys Pasture to Blair