Isom Palmer, whose name has various spellings, was born to Martin and Sarah (Hardwick) Parmer. In 1825, the Palmer (Parmer) family moved to Texas, settling near Nacogdoches the next year, and participated in the 1826 Fredonian Rebellion. Palmer fought under Capt. John M. Bradley during the Siege of Bexar in late 1835. He then served as sergeant-at-arms at the signing of the Texas Declaration of Independence at Washington-on-the-Brazos. He later wed Laura E. Dougherty and moved to Brazos County in the early 1870s.