Almost immediately after leaving Cambridge Spencer was elected to parliament for South Northamptonshire as a Liberal, before departing for a tour of North America. He returned in December 1857, and within a few days his father died, leaving him as the new Earl Spencer. He was sworn of the Privy Council in 1859 and made a Knight of the Garter in 1864. Spencer split from other whiggish aristocratic Liberals in 1866 on the issue of Russell's reform bill, which he supported, and his loyalty was rewarded by his appointment as Lord Lieutenant of Ireland when Gladstone returned to power in 1868. Ireland came to be a major preoccupation of the remainder of Spencer's long political career. In this first tenure as Lord Lieutenant, he had to deal with implementation of the disestablishment of the Church of Ireland in 1869 and of the Landlord and Tenant (Ireland) Act 1870, both of which measures he strongly supported. Spencer, in fact, went further than most of his ministerial colleagues, including Gladstone himself, in arguing for the setting up of government tribunals to enforce fair rents on Irish landlords (a reform which would eventually be introduced by the Land Law (Ireland) Act 1881).