From 1687 to 1689 Johnson was an Assistant of the
Royal African Company. At the
1689 English general election, he was returned as Tory
Member of Parliament for
Aldeburgh on the interest of his brother Henry. Also in 1689, he was appointed Commissioner for assessment, for Middlesex, Suffolk and Aldeburgh to 1690, and Deputy Lieutenant for Tower Hamlets at least to 1702. He was not active in the Convention Parliament, but served on six committees including one to consider the management of the East India trade, one for the bill for restoring corporations, and one on a petition from the Royal Africa Company. At the
1698 English general election, Johnson and his brother both stood at Aldeburgh, where they were returned unopposed again, and he stood on his own at
Orford, where he was defeated. He petitioned, and then in February 1700, he went on a long voyage to the East Indies and China. The petition was finally declared in his favour after the dissolution of Parliament. From the first general election of 1701, he stood only at Aldeburgh, where he was returned unopposed then and in the second general election of that year. As a Tory, he supported the motion of 26 February 1702 to vindicate the Commons’ proceedings over the impeachment of the Whig ministers in the previous session. He was committee member of the East India Company again from 1702 to 1705. He was not recorded as voting on the Tack on 28 November 1704. In 1709 he became an Elder Brother of
Trinity House for the rest of his life. ==Death and legacy==