Crittenden began a college preparatory curriculum at Pisgah Academy in Woodford County.[5] He was then sent to a boarding school in Jessamine County.[5] Among his classmates were Thomas Alexander Marshall and Francis P. Blair.[3] Crittenden became especially close friends with Blair, and later political differences did little to diminish their friendship.[6] After a year at boarding school, Crittenden moved to the Lexington, Kentucky, home of Judge George M. Bibb to study law.[5] He began his tertiary studies at Washington College (now Washington and Lee University) in Lexington, Virginia.[7] During his brief tenure there, he studied mathematics and belles-lettres and became friends with Hugh Lawson White.[7] Crittenden was dissatisfied with the curriculum at Washington College and matriculated to the College of William and Mary.[7] He studied under St. George Tucker and became acquainted with John Tyler.[5][8] Crittenden completed his studies in 1806, and was admitted to the bar the following year.[7][9] He began his practice in Woodford County, but as central Kentucky was well already supplied with able lawyers, he moved to Logan County, Kentucky, on the then western frontier and opened his practice in Russellville.[5] At age twenty-two, he was appointed by Governor Ninian Edwards of Illinois Territory as its attorney general.[1] The following year, Edwards also made Crittenden his aide-de-camp.[10][a]