The Indiana State Legislature passed an omnibus county bill on 7 February 1835 that authorized the creation of thirteen counties in northeast Indiana, including Marshall. It was named for U.S. Chief Justice John Marshall, who died in 1835. The government of the county was organized in 1836, during the early years of settlement and before the forced removal of the Potawatomi people in 1838. The first settlers had arrived in the county in 1835; they arrived as a result of the end of the Black Hawk War as well as the completion of the Erie Canal. They consisted primarily of settlers from New England, "Yankees" descended from the English Puritans who settled New England in the colonial era. They were mainly members of the Congregational Church, although due to the Second Great Awakening many of them had converted to Methodism and some had become Baptists before migrating to the new area. As a result of this heritage, some place names in Marshall County are named after places in New England, such as Plymouth, which is named after Plymouth, Massachusetts, the site where the "Mayflower" landed in 1620.