Port Huron, a city and the county seat of St. Clair co., Michigan, port of entry of the customs district of Huron, on the St. Clair river and at the mouth of Black river, which is here crossed by two bridges, l 1/2 m. from the foot of Lake Huron, 53 m. N. N. E. of Detroit, and 110 m. E. by N. of Lansing; pop. in 1860, 4,371; in 1870, 5,973; in 1874, 8,240. It is the terminus of the Chicago and Lake Michigan railroad, and by ferry to Port Sarnia, Canada, on the opposite side of the St. Clair river, it connects with the Great Western line. The Grand Trunk railway crosses the St. Clair at Fort Gratiot, 1 1/2 m. N., to which point two horse railroads have been constructed. The Black river brings down immense quantities of logs, which give employment to a large number of lumber and shingle mills. There are also three ship yards and two dry docks. The trade in fish is important. The customs district embraces all the coast of the state bordering on Lake Huron, and has a large domestic and foreign commerce. The traffic by rail with Canada is extensive. The city has a fire department, gas works, water works, a fine court house, two national and two private banks, a savings bank, several hotels, four large public school houses, two daily and three weekly newspapers, and nine churches.

The first frame house on the site of Port Huron was erected in 1819. It was incorporated as a village in 1835, and as a city in 1857.