In 1817, Blackford was appointed Chief Justice of the Indiana Supreme Court by Governor Jonathan Jennings to replace Chief Justice John Johnson who had died after less than a year on the bench, and before the court had issued its first decision. Jennings informed Blackford of his decision as the two walked arm-in-arm from Johnson's grave following his funeral service. Blackford at first refused, saying he was too young and inexperienced. However, there were less than seventy lawyers in the entire state at that time, the majority of which belonged to other factions of the party, or had not lived in the state long enough to qualify for the job. Jennings and Blackford were the only two members of the government who came from New Jersey, increasing Jennings' sentimental desire to see Blackford appointed. Despite Blackford's refusal, Jennings appointed him to the court and he was easily confirmed by the state senate to his first seven-year term.