Eugene Casserly was born on November 13, 1820, in Mullingar, County Westmeath, Ireland, and immigrated to the United States with his parents in 1822, settling in New York City.

Casserly's father prepared him for a college education and he attended and graduated from Georgetown University in Washington, D.C.

Before moving to San Francisco, California, in 1850, Casserly served on the New York City corporation counsel from 1846 to 1847.

After resigning from the United States Senate, Casserly resumed practicing law in San Francisco and served as a member of the California Constitutional Convention in 1878 and 1879.

This article incorporates public domain material from the Biographical Directory of the United States Congress