Sarnia was enjoying a growth spurt in the late 1860's They had achieved town status a few short years ago and the arrival of not one but two railroads was definitely a source of pride. The Great Western Railway began servicing the Sarnia area in 1858 while the Grand Trunk Railway began its service the following year in 1859.

The arrival of these great companies greatly stimulated Sarnia's growth. In 1889 a decision was made by The Grand Trunk Railway to link directly to the United States by tunneling directly under the St. Clair River. This was a massive undertaking let alone a marvel of engineering.

Not only was it the first time that a tunnel was built under a river but it was the first time a tunnel had been built to join two equally different and sovereign nations. The construction was accomplished through the development of original techniques for excavating in a compressed air environment. A gigantic hydraulic tunneling shield weighing 72 tonnes was lowered into place. Inside the shield were seats provided so the workers could claw the clay from the front of the shield enabling forwards movement. Attached to the rear was a rotating arm especially designed to lift the half-ton cast iron section that formed the tunnel wall.

With a workforce of 700 men working with picks, shovels and an army of mules, assisted by a derrick powered by a 50 horsepower hoisting engine, and half of the workforce on either side of the river they battled their way towards each other. These brave pioneers toiled for a period of 13 months, 24 hours a day,7 days a week. These pioneer tunnelers didn't have it easy, not only did the have to battle water leaks, pockets of gas and quicksand they literally had to dig the tunnel by hand. They started out using shovels and spades but they would bend, and the blue clay was so sticky that they had scrape it off each shovelful.

It was extremely tough slugging for the 17 cents per hour wage the job commanded. They complained about working in the air chambers as they were hot and dirty so the company dropped their pay down to 12 cents per hour but were given a 14 hour day to make up the difference in pay. On August 20, 1890, workers from both sides of the river punched through the last few feet of clay to discover that the cast iron tunnel shields that each team used were only a mere 1/4 inch out of alignment.

A signal was given and whistles blasted from both Sarnia and Port Huron. The engineering feat of the century was finally completed. For many decades the community was referred to as the Tunnel City. Unfortunately the creation of this marvel did not come cheap. Three workers died in its construction and several railroad workers were asphyxiated before the advent of electric trains in 1904. The tunnel was in daily use until 1995. The old tunnel was still in perfect condition, quite remarkable for a structure that was over 100 years old. The only reason it was replaced was because it could not handle the modern double decked cars.