Alpha Gamma Rho considers the Morrill Act of 1862 to be the instrument of its inception.

Having been signed by President Abraham Lincoln in 1862, it provided land and other financial support to establish one institution of higher learning in the agricultural and mechanical sciences within each state.

Sixteen men signed the fraternity's charter at the Claypool Hotel in Indianapolis on April 4, 1908.

The first non-state (private) associated chapter (Beta Psi) was at Delaware Valley University in Doylestown, Pennsylvania.

[2] In 2018, the chapter at University of Minnesota was suspended after one of its members, Dylan Fulton, was found dead following a night of drinking.