McMichael served in a number of political positions throughout his life. He began his service as a police
magistrate and then as an
Alderman in the
Spring Garden neighborhood of Philadelphia. McMichael began his political career in 1838 as a
Jacksonian Democrat but drifted away from that ideology and became a
Democrat, a
Whig in 1843 and a
Republican in 1857. McMichael was attracted to the Republicans' strong stance on high tariffs and less so on their abolitionist beliefs. In 1843 he was elected
Sheriff of Philadelphia County, serving until 1846. His newspaper also argued for a new street numbering system to replace the city’s confusing address system, which often numbered houses in the order they were built rather than by location and resulted in fractional house numbers along streets. Thoroughout the
American Civil War, He saw the succession of the South as treason and that slavery was incompatible with re-consolidation of the Union and Confederacy. After the assassination of Lincoln, he became a strong advocate for Republicanism and anti-slavery. In 1865, McMichael defeated Democrat
Daniel M. Fox by 5,000 votes and was elected as the Mayor of Philadelphia. While he was mayor, the
Fairmount Park Commission was established. McMichael served on the board and, once his term ended in 1869, was appointed as president of the commission, serving until his death. He was offered a position as minister to Great Britain by President
Ulysses S. Grant but declined. ==Personal life==