St. Joseph is a city in the US state of Michigan. It was incorporated as a village in 1834 and as a city in 1891. As of the 2010 census, the city population was 8,365. It lies on the shore of Lake Michigan, at the mouth of the St. Joseph River, about 90 miles east-northeast of Chicago. It is the county seat of Berrien County. It is home of the American Society of Agricultural and Biological Engineers. St. Joseph and Benton Harbor are locally known as the "Twin Cities". ^ Coolidge 1906, p. 25.