Complex sentence: In 1861, Edmunds resigned as comptroller when he was appointed by U.S. President Abraham Lincoln, commissioner of the General Land Office of Washington, and held it until 1866, when he became postmaster of the Senate which he resigned in 1869.
Split into simpler sentences: In 1861, Edmunds resigned as comptroller when he was appointed by U.S. President Abraham Lincoln, commissioner of the General Land Office of Washington, and held it until 1866. After resigning from the land office, he became postmaster of the Senate which he resigned in 1869.