Following graduation from the College of William and Mary, George enlisted in the Army and was given charge of the garrison at Fort Stephenson, Ohio. His successful defense of the fort during the War of 1812 made Croghan a national hero.
He married Serena Livingston of New York in 1817, and they maintained a plantation near New Orleans while he served as Postmaster there. He had a troubled life with drinking and gambling problems.
Continuing in military service, Colonel Croghan fought in the Mexican War with Zachary Taylor and died of cholera in New Orleans. His son and grandson inherited Locust Grove.