The Lawrence family from Pennsylvania settled around Lawrenceville by 1818 where a United Bretheren Church was established nearby in 1819 or 1820. John Sunman, Sr. and his son Tom arrived in 1819 from Holtby near York, England. They settled west of Penntown where he, his wife Ellan and two sons are buried on the point across the lake-in Indian Lake campground.
Napoleon was among the earliest settlements in the area having been platted in 1820.It was located at the junction of the Michigan Road from Madison to Indianapolis and road from Lawrenceburg to Napoleon. The Elias Conwell house built in 1822 at that junction is still standing as is the nearby Central Hotel built about the same time.
Many of the early churches in Dearborn and Ripley Counties were Methodist or Baptist. The Baptist Church was particularly strong among New Englanders. A Baptist Society was established in the Penntown area in 1823 as a branch of the Little Cedar Grove Baptist Church south of Brookville. It became the Pipe Creek Baptist Church in 1832.
Franklin Baptist Church was established south of present day Negangard's Corner in 1823 as a branch of 2nd Manchester Baptist Church at Hogan Hill. The Methodists also began meeting in various homes and schools around Clinton about 1830. St. Pauls Methodist Church south of Sunman is the outgrowth of this organization.
The first Catholic Church in southeastern Indiana was built at McKenzie's Crossroads (Dover) in 1824 by Irish Catholics from Maryland. They had established a congregation there as early as 1820. Just east of Dover is an area still known as "Tipperary".
Some Germans had been among the earliest settlers in the vicinity, Phillip, Casper, and Jared Michael from Baden purchased land one mile southeast of present day Weisburg in 1817 and 1818. They were part of the first large German migration to America in the 19th century.
These immigrants of 1817 had suffered a series of disastrous crop failures culminating in unusually extreme weather in 1816, "the year without a summer". The immigration was a spontaneous movement drive by panic and despair.
A sense of restlessness and instability had also been created by the Napoleonic Wars which the restoration of the old regimes in 1815 could not subdue. Many of the immigrants came from southwestern Germany where Napoleonic sentiment was particularly strong. The area of heaviest emigration was from the Dreisamkreis around Freiburg, Baden.
Crops improved in southern Germany in the fall of 1817, and many of the people who had attempted to leave experienced great difficulties and failed to reach America. Consequently, emigration became unpopular, and it was not until around 1830 that Germans once again began to migrate to America in any great numbers.