Washington is one of the eastern boundary townships crossed by the main line of the Pennsylvania Railroad and Highway Route 53. It was organized January 6, 1831, with territory taken from Summerhill, Allegheny and Cambria Townships. Cresson Township and a portion of Portage Township were later taken from Washington Township. The old Portage Railroad from Hollidaysburg to Johnstown crossed the township. This railroad attracted business and a village grew up at the "Foot of Four," which later was incorporated as the Borough of Lilly. In 1850 at the time of the operation of the Portage Railroad, Richard and Alex White conducted a large lumbering operation and coal mine in the township near Lilly. Washington Township was the location of one of the first coal mines in the county. While digging a well for water to operate the engine on Plane 6, a vein of coal was discovered, later known as the Lemon vein. It is recorded that in 1840 there were approximately 35 coal miners living in Washington Township. Subsequent to 1880, coal mines were opened in Washington Township by the Sonman Coal and Coke Company, Standard Coal Company, The Lilly Coal Company, and Mr. Carton Leahey. In 1950 the population of the township was 1,370.