Lot Myrick Morrill was born in 1813 in Belgrade, Maine. He worked as a clerk, taught school, attended Waterville College (now Colby College), studied the law, and was admitted to the state bar in 1839. While practicing the law in Augusta, Maine, Morrill became involved in politics, serving as a state representative from 1854 to 1855.

Morrill left the Democratic party in 1856 because of the party’s stance on slavery, so it was as a Republican that he was elected to the state senate, where he was its president. From 1857 to 1861, Morrill served as Maine’s governor before being elected to fill a vacancy in the United States Senate. A delegate to the 1861 “Peace Convention,” Morrill remained in the United States Senate from 1861 to 1869, voting for Reconstruction, for giving former slaves equal rights, and for the conviction of President Andrew Johnson on articles of impeachment.

Though he declined to run for reelection in 1868, Morrill was back in the Senate by 1869, filling a vacancy. He served until 1876, when President Ulysses S. Grant tapped him to become secretary of the treasury. Though Morrill had declined an earlier offer from Grant to become secretary of war, he accepted the treasury portfolio and remained in that position until the end of the Grant administration in 1877. After leaving office, Lot Myrick Morrill returned home to Maine, where he served as collector of customs at the port of Portland until his death in 1883.