In the 1830s in the aftermath of the Cincinnati riots African Americans began to the to move to southern Mercer County on the Ohio frontier. Charles Moore, an African American founded the town of Carthagena. John Randolph, a Virginia plantation owner, decided to free his slaves on his death. He bought land for them in the southeastern part of the County and had White locals build cabins for the new Black settlers. In 1846 400 recently freed slaves traveled to their new homes on the Miami-Erie Canal. At New Bremen, a mob of local Whites was waiting for them. They would not allow them to land. In the aftermath of the riot, a meeting of representatives from throughout Mercer County met and proposed not allowing any more Blacks to move into the County and organizing an economic boycott of the current Black residents. At one time in the Antebellum Era Mercer County had the 4th highest per capita Black population in Ohio. And Marion township had the largest portion of them. According to the 2000 Census there no Blacks living in the County at that time. It has increased a little since then. Oh and the Randolph Slaves never got their land.