Prior to the arrival of the European and American immigrants into the Allen area, Caddo and Comanche Indian tribes inhabited the region. The Indian tribes migrated westward as the early settlers entered the area. The tribes were eventually removed to the Indian territory to the north of the Red River. One of the last known conflicts between the early settlers and the Indians took place in 1844 along Rowlett Creek near the existing railroad. A historic marker along SH 5 near Rowlett Creek commemorates the event.
Immigrants of European descent began arriving into the Allen area in the early 1840's in search of free land, traveling the Texas Road and the Central National Road constructed by the Republic of Texas. A stage line ran from Bonham through McKinney to Allen and Plano, crossing Rowlett Creek where SH 5 now crosses. Allen was part of the Peter’s Colony Land Grant from the Republic of Texas to the Texas Emigration & Land Company
The Houston and Texas Central Railroad (H&TC), constructed through Allen in 1872, laid out the original township of Allen. The H&TC was acquired by J.P. Morgan & Company in1877 and by the Southern Pacific in 1883. In 1918, the H&TC erected a combination freight/passenger depot in the Allen Central Business District. The first train robbery in Texas took place in Allen on February 22, 1878, when Sam Bass and his associates pillaged the train. Allen was a short ride from their hideouts in the Elm Trinity brush lands
In 1907 the Texas Traction Company (Interurban) purchased right-of-way on the west side of the H&TC main line track to construct the Interurban line through Allen as a stop on its route from Denison to Dallas (completed in 1908). In 1915 a devastating fire destroyed most of the business district between the Interurban tracts and the railroad. The Interurban closed in 1948 and the population of Allen declined to 400 in 1950.
The town was officially incorporated in 1953. Home Rule Status was adopted in 1979 with a Council/Manager form of government. The construction of US 75 in 1960 had a similar impact on Allen’s future as the railroad almost a century before. In the 1980’s, Developmental Learning Materials and InteCom, Inc. relocated to Allen, leading the way for further corporate startups and relocations
The Allen Heritage Guild was established in 1996 to assure tomorrow’s heritage by recording past and current milestones for the city.