The Port Huron, Michigan - Sarnia, Ontario Border Crossing

The�border crossing between Port Huron and Sarnia, Ontario, has always been an important spot on a key trade route.

Indians from the Chippewa, Ojibway, Huron, and Ottawa tribes, whose nations included land on both sides of the St. Clair River, braved its tricky currents, crossing in canoes with cargoes of tobacco, corn, and furs. British and French fur traders traveled the Indian trails, from Toronto to the east, Detroit and Chicago to the west, and Sault Ste. Marie to the north, that met here.

Before, and during, the U.S. Civil War, Port Huron was a northern terminal of the Underground Railroad. Any farm house from that era, or any of the Victorians that dot the city's south side, could have been stations where friendly "conductors" hid escaped slaves until they could reach the next safe house, and eventually freedom in Canada.

In 1865, when the war had ended, bands of expatriate Confederates gathered in Canada and planned to invade the United States from Sarnia. Ontario milita dispatched from nearby London prevented the invasion from taking place.

The Grand Trunk Railway of Canada incorporated in 1851. By 1856, it linked Toronto and Montreal. Three years later, the line reached Sarnia. Ferries carried freight trains across the St. Clair River until 1891, when the world's first rail tunnel linking two countries opened. For over a century, the tunnel carried goods from Canada to Chicago and American inland markets. In 1995, a new tunnel that could accommodate larger rail cars opened parallel to the old one, which was closed.

Ferries handled vehicle traffic until 1938, when the Blue Water Bridge opened. In 1997 a second span opened, for eastbound traffic into Canada, and the original span became one-way westbound into the United States. The Blue Water Bridge connects Ontario route 402, the freeway from Toronto, with Interstates 69 and 94. This crossing is the fourth busiest on the U.S. - Canada border, and a key spot on roads whose importance the North American Free Trade Agreement has increased.