[8] The Fort Gratiot Light marks the entrance to the St. Clair River from Lake Huron (going south) in the southern portion of Michigan's Thumb.

A staunch supporter and ally of the Fifth Auditor, Lewis had branched out into the business of lighthouse construction, and as the frequent low bidder, was being awarded a growing number of contracts to fulfill the nation's need for navigational aids on the East Coast.

Lewis sub-contracted the construction of the tower and keeper's dwelling that would become known as the "Fort Gratiot Light" to Daniel Warren of Rochester, New York.

Work commenced on the structure, but appears to have been running far beyond the scope of the original bid, since Congress appropriated an additional $5,000 for the project's completion on April 2, 1825.

McDougall's reports indicated that the stairs were so steep that they had to be climbed sideways, and the trapdoor into the lantern room was barely large enough for a man to squeeze through.

Soon after its establishment in 1852, the new US Lighthouse Board determined that the Lewis lamps universally accepted by the prior Pleasonton administration were significantly inferior to the French Fresnel lenses being adopted throughout the rest of the world.

[13] As lake shipping continued to rise dramatically in the early second half of the century, it was determined that the Fort Gratiot Light needed further upgrading.

To this end, in 1862 the government increased the height of the tower to 82 feet (25 m), and the fourth-order Fresnel was replaced with a larger third-order lens, showing a fixed white light.

In 2009, these plans were jeopardized, when city council rejected a deed offered by the federal government because it found the financial requirements too burdensome.