| 1837 | April 4, 1837, a charter was granted for the construction of the Pittsburgh, Kittanning & Warren Railroad. | |
| 1852 | Fifteen years later, construction of the railroad began. April 14, 1852, the name of the railroad changed to the Allegheny Valley Railroad, suggested by Josiah Copley. | |
| 1855 | December 11, 1855, the Allegheny Valley Railroad opened for business at the Rosston station. (mouth of Crooked Creek) | |
| 1856 | January 23, 1856, the Allegheny Valley Railroad opened for business at the Kittanning Station. | |
| 1860 | Kelly Station was built and opened immediately to service the AVRR. | |
| 1863 | The first telephone lines were erected in Armstrong County . These lines were built along the Allegheny Valley Railroad. At a later date, the lines became absorbed by Western Union . | |
| 1865 | The Allegheny Valley Railroad extended its tracks to service Monticello Furnace with ore to make iron that is of better quality. | |
| 1867 | The Allegheny Valley Railroad extended its tracks to the Phillipston, 3 miles north of the mouth of Redbank Creek. Phillipston became the main service station for the locomotives along the AVRR. June 25 1867, engine No. 17 was the first engine to make its way to Phillipston. Also William Phillips urged immediate construction on the extension of the AVRR to Brady's Bend . The track was extended and completed to Venango City where it opened for business in December 1867. | |
| 1870 | The Allegheny Valley Railroad was completed from Pittsburgh to Oil City . The track opened for use February 2 1870 . | |
| 1874 | At the mouth of Redbank Creek, the “Low Grade Division” or also know as the “Redbank Junction” was completed. This track branches off the AVRR and travels to Driftwood, PA where it then is known as “Bennett's Branch”. The Low Grade Division also branches 5 miles down Redbank Creek at Lawsonham where it goes through Rimersburg to Sligo where it is then called “ Sligo 's Branch”. The Sligo Branch was constructed to harvest the immense lumber and coal resources of Clarion County . | |
| 1886 | Phillipston's service station among other businesses burned down. Due to the importance of the station, it was quickly rebuilt without hesitation. | |
| 1892 | The borough of Johnetta was established where later a station was built. | |
| 1900 | August 1, 1900, Pennsylvania Railroad Company took over operations of the Allegheny Valley Railroad under lease. When the lease was handed over to the PARR Co., the name of the railroad changed to the Buffalo & Allegheny Division and the track was extended to Buffalo, NY . The Low Grade Division then connected from Driftwood, PA to the Harrisburg & Buffalo mainline. | |
| 1910 | April 7, 1910, The Pennsylvania Railroad Company acquired possession of the entire line. PARR Co. then had new stations built at the towns of Johnetta, Kittanning, and Templeton along the railroad. They also had modern steel bridges built over the Kiskiminetas River, Redbank Creek, and Mahoning Creek. | |
| 1915 | Construction of the East Brady Tunnel began. This tunnel's purpose was to replace the section of the track that traveled 7 miles around the bend into East Brady. This tunnel cut off 6 miles of the trip and avoided the high degree bends of the other track. | |
| 1916 | The East Brady Tunnel was completed and opened on May 28, 1916 to serve the locomotives of the railroad. | |
| 1941 | The “Low Grade Division” or the “Redbank Junction” quit passenger operations. | |
| 1992 | The railroad corridor that was once the Allegheny Valley Railroad was purchased and is currently being used for a non-motorized recreational trail. This is what has now become the Armstrong Trail. | |
| 1997 | October 1997, 1.2 miles of trail were completed through Ford City with an asphalt surface. In addition, 1,100 feet was completed just south of Ford City with a crushed limestone surface. | |
| 1998 | September 1998, 1.1 mile of trail connecting Manorville and Kittanning was completed with a crushed limestone surface. | |
| 2002-2003 | Within this time period, 2 miles of trail were completed through Kittanning with an asphalt surface, 2 miles of trail from Kittanning to just shy of the mouth of Cowanshannock Creek where a ramp was constructed to take trail users to SR 1033 was completed with a crushed limestone surface. In addition, 1 mile of trail was completed from Templeton to the mouth of Mahoning Creek with a crushed limestone surface. | |
| 2005 | In summer of 2005, 4 miles of trail were completed from Cowanshannock Creek to Army Core of Engineers Lock and Dam 8 with a crushed sandstone surface. NOTE: Just shy of Hayes Run a ramp was constructed to take trail users to SR 1033. In fall of 2005, approximately 1.5 miles of trail were completed just north of the ACE Lock and Dam 8 with a crushed sandstone surface. | |
| 2006 | In fall of 2006, the Cowanshannock Creek Trail, a 1 mile spur off the Armstrong Trail, was completed with a crushed limestone surface. The Cowanshannock Trail takes trail users on a 1 mile walk/ride to the Buttermilk Falls. | |