In 1967 Rep. Amens replaced Keeter as the head of credit mobilier, which founded by and working with Union Pacific allowed people involved to sign contracts with themselves to get double the profit while working on a government sponsored rail line. In that year Amens offered discounted shares of the corporation to members of congress, which protected the deal as congressmen who accepted those shares let a blind eye and accepted the inflated costs of the project.

The story was leaked to the general public in 1872 by Herry McComb who provided the materials to New York Sun.