In 1628 Angus married Lady Anne Stuart, second daughter of Esmé Stewart, 3rd Duke of Lennox, Charles I being a party to the marriage contract.
Judged by his vacillation in this matter Angus would seem to have had a large share of that spirit of irresolution which was the chief characteristic of the political careers of his half-brother and nephew and the third and fourth dukes of Hamilton.
[3] Angus returned to Scotland in 1641, when he appeared in parliament, and his right to sit as a peer's eldest son being questioned and decided against him, he was turned out, together with some others of the same rank.
He held this post till 1653, when he resigned it in favour of his brother George Douglas, 1st Earl of Dumbarton, but it does not appear that he saw any active service.
At that ceremony he officiated as high chamberlain, and in the following April he was created Earl of Ormond in the Peerage of Scotland, (the subsidiary title of this earldom was Lord Bothwell and Hartside), with remainder to the heirs male of his second marriage with Lady Jane Wemyss, eldest daughter of David, 2nd Earl of Wemyss, his first wife having died 16 August 1646, in her thirty-second year.
[3] At the assembly which met at Edinburgh, and afterwards at Dundee, in July 1651, the earl took a leading part in the opposition to the Western Remonstrance; but after the departure of Charles II to the continent he retired into private life.