He served as Solicitor General for Scotland (1802–1805) and as Lord Chief Commissioner of the Jury Court (1815–39).
[1] His political career was affected by his father's periodic financial problems, as sometimes the family had substantial wealth and sometimes it was in difficulties, forcing Adam to concentrate his attention on his legal practice.
His most important contribution to Scottish Law was probably the introduction of trial by jury on civil (non-criminal) cases.
[1] Blairadam House, where William was born, lies just north of Kelty in Fife, but on an isolated side road.
Adam took a very hard line on American issues in the early part of his political career.
He was critical of his future political leader Lord North for being too conciliatory before the outbreak of fighting.
However, after pursuing an independent course up to 25 November 1779, he then announced in the House of Commons that he was now going to support Lord North.
After that, despite his past animosity to Charles James Fox, Adam advocated the Fox-North Coalition, as the only way to stop Lord North's party becoming politically irrelevant.
Adam was active in gathering detailed information about the Scottish constituencies, to help his political associates.