The churches Peter was ministering to in Virginia joined the Tennessee Synod. Peter left Virginia moved to Pennsylvania and became a member the Evangelical Lutheran Synod of Western Pennsylvania. In 1822 Peter moved to Newark, Ohio. In Ohio he left the call of full time ministry and pursued secular business during the week. He did continue to labor independently preaching on Sabbath days at Lutheran and other churches in Ohio when the opportunity presented itself. About the year 1832 he and his wife joined the Methodist Episcopal Church and Brother Schmucker began to serve as a Methodist minister. In the fall of 1838 he was persuaded to enter the Ohio Conference in the German mission in Cincinnati, Ohio. In two years the society grew from 30 to 80 members. In the fall of 1840 he was appointed to Louisville, Kentucky, forming a society there that was able to support itself in its first year. “Fearlessly he attacked the strongholds of Satan, and thereby caused soon a great persecution against the "new sect." Stones flew freely into the old frame school-house in which he was preaching, and once a gun was even fired into it, without, however, doing any serious injury.” In the spring of 1842 Brother Schmucker was sent to New Orleans. After his return from New Orleans he was sent to Evansville, Indiana, but his health failed, and he had to rest six months. In the fall of 1843 he was appointed Superintendent of German missions in the Ohio Conference. The conference was so successful that it was necessary to divide it into two districts. From 1844-1848 Brother Schmucker was put in charge of the Cincinnati district that included all the German missions from Columbus, Ohio, to Evansville, Indiana. He extended the work of this district to Michigan and laid the foundation for a German church in Detroit. He also visited New Orleans a second time. In the spring of 1848 his health gave way and he could not continue his work as the leader of the district. From the Fall of 1848 until his death in 1860 Brother Schmucker was not well and he was mainly confined to his room, his faith in God strong to the end. William Nast in Brother Schmucker's obituary wrote: [Brother Schmucker was] a man of such deep piety, long pastoral experience, general intelligence, sound Biblical theology, and pleasing and venerable address as brother S. possessed. He was a man of no ordinary intellect, had read much, and was "great in the Holy Scripture."