The next year, Howe was elected to the assembly as a liberal reformer, beginning a long and eventful public career. He was instrumental in helping Nova Scotia become the first British colony to win responsible government in 1848. He served as premier of Nova Scotia from 1860 to 1863 and led the unsuccessful fight against Canadian Confederation from 1866 to 1868. Having failed to persuade the British to repeal Confederation, Howe joined the federal cabinet of John A. Macdonald in 1869 and played a major role in bringing Manitoba into the union. Howe became the third Lieutenant Governor of Nova Scotia in 1873, but died after only three weeks in office.