Jefferson writes John Holmes, a Congressman from Maine, criticizing the Missouri Compromise which maintains the balance of free and slave states in the Union by admitting Maine with Missouri. In 1819, a bill to admit Missouri to the Union was before Congress when a New York representative proposed an amendment prohibiting slavery in the new state. Though this measure did not pass, Jefferson sees the debate surrounding the Compromise as an example of unprofitable northern interference in a southern institution. He has completely withdrawn from his earlier calls for abolition, viewing it as a problem so complex as to be intractable and therefore best left to the next generation to accomplish. Jefferson describes the Missouri Compromise as a "fire bell in the night" and the "knell of the Union."