In 1854, Colfax ran for Congress again, this time as nominee of the short-lived Indiana People's Party, an anti-slavery movement which formed to oppose the Kansas–Nebraska Act. Colfax won and was reelected six times, representing Indiana's 9th congressional district from March 4, 1855, to March 3, 1869. During his House service, Colfax became a member of the leadership as chairman of the Committee on Post Office and Post Roads, a post he held from 1859 to 1863.
In 1854, Colfax ran for Congress again, this time as nominee of the short-lived Indiana People's Party, an anti-slavery movement which formed to oppose the Kansas–Nebraska Act. Colfax won and was reelected six times, representing Indiana's 9th congressional district from March 4, 1855, to March 3, 1869. During his House service, Colfax became a member of the leadership as chairman of the Committee on Post Office and Post Roads, a post he held from 1859 to 1863.