On November 15, 1826, Crittenden married Maria Knox Todd, a widow who was the daughter of Judge Harry Innes. Crittenden took Todd's three children as his own, and the couple had two more children: John and Eugene. Todd's daughter Catherine married her stepbrother, Crittenden's son Thomas; their son, John Jordan Crittenden III, was killed at the Battle of the Little Bighorn. Maria Knox Todd Crittenden died on September 8, 1851, of an unknown illness.