The paper grew to prominence under McMichael, who became sole publisher in 1854 (when co-owner Robert Montgomery Bird died). He remained publisher until his own death in 1879, though his sons took over active operations in his final years. McMichael served in a number of political positions throughout his life. He began his service as a police magistrate and then an Alderman in Philadelphia. As an alderman, he also served as Justice of the Peace for the County of Philadelphia. In 1843 he was elected Sheriff of Philadelphia County, serving until 1846. McMichael served as Sheriff during the Philadelphia Bible Riots of 1844. After serving his three-year term as sheriff, McMichael was ineligible to serve again for the next four years. In 1854, McMichael chaired the Executive Consolidation Committee, which merged the city of Philadelphia with many of the surrounding districts into a single political entity. After the Civil war, McMichael was elected the first Republican Mayor of Philadelphia, serving from 1866 through 1869. In 1867, while serving as Mayor, McMichael also became President of the newly created Fairmount Park Commission, a position he held until his death in 1879. In 1873 he was appointed a delegate at large to the fourth Constitutional convention of Pennsylvania. This resulted in the establishment of the Pennsylvania Constitution of 1874. A statue of McMichael, unveiled in 1882, sits in Philadelphia's Fairmount Park at Sedgely Drive and Lemon Hill Drive. The East Falls district of Philadelphia named McMichael Park after Morton McMichael. Morton McMichael Elementary School is also named in honor of him. It is a part of the Philadelphia public school system. McMichael was a founding member and fourth President of the Union League. The McMichael Room in the Union League building is named in his honor. He is buried at Laurel Hill Cemetery.