Kerr moved to Ohio in 1792. He served in various positions in the Northwest Territory. After the founding of the State of Ohio he was elected in 1804 and 1810 in the Senate of Ohio. In 1808 he moved for the first time in the House of Representatives from Ohio and was re-elected three times. In addition, he served as a Brigadier General in the British- American War and was responsible for supplying the troops in the northwest with provisions.
In 1814 he was elected to the U.S. Senate to take over the vacant seat of Thomas Worthington, who had successfully running for governor of Ohio. Kerr retained the seat in the Senate until 1815. Reelection he did not seek.
1826 was his large farm bankrupt. Then he moved to Memphis ( Tennessee) and later to Lake Providence, Louisiana, where he died in 1837.