Macdonald was
Member of Parliament for
Hindon in
Wiltshire, from 1777 until 1780, and then for
Newcastle-under-Lyme, from 1780 to 1792, a seat where his father-in-law had a strong influence. The
1792 Slave Trade Bill passed the House of Commons; mangled and mutilated by the modifications and amendments of
Pitt,
Earl of Mornington,
Edward James Eliot and MacDonald, it lay for years, in the House of Lords.
Judicial career Macdonald was appointed as second judge of the
Carmarthen circuit in Wales in 1780. He was promoted as
Lord Chief Baron of the Exchequer in 1793, and served in this post until he retired in 1813, with failing eyesight. ==Personal life==