In 1774 Dashwood contested
Wigtown Burghs on the interest of his brother-in-law
John Stewart, 7th Earl of Galloway. With each candidate receiving only two of the four votes, Dashwood's opponent was initially declared the winner, but on petition the result was reversed and Dashwood was returned as
Member of Parliament. He voted in support of Lord North in the 1770s. In 1779, Dashwood succeeded to the
baronetcy on the death of his father on 10 November. He married Helen Mary Graham, daughter of John Graham of Kinross on 17 July 1780. Helen's uncles were MPs
William and
Robert Mayne and in 1780 he decided to stand at
Canterbury, which had been a Mayne seat. Dashwood was unsuccessful at Canterbury and equally unsuccessful in obtaining a lucrative government office. In 1783 he was appointed Gentleman of the Privy Chamber, an honorary appointment. After he came into his inheritance Dashed sold most of the family estate to pay further debts. Dashwood was a friend of the
Duke of Marlborough and was returned unopposed on the Duke's interest at the
pocket borough of
Woodstock at the 1784 election. He was returned unopposed at each election until 1820. Dashwood tried several times in 1794 to persuade
William Pitt the Younger to give him a peerage, as he was a loyal supporter of the government. Unhappily for Dashwood no preferment was forthcoming. ==Later life and legacy==