Fort Gratiot - Port Huron, MI
First tower- 1825 collapsed 1828 due to poor construction and erosion.
Second tower 1829, height increased from 74 feet to 82 feet in 1861.
As to why it has a green lens today, I can't find that answer. It was once changed from a fixed light for an interesting reason.
According to Terry Pepper's site
The growing amount of railroad traffic in Port Huron created confusion for many mariners when the locomotive headlamps were seen to shine as brightly as the Fresnel in the lighthouse. The problem was remedied in 1867, when the "fixed white" lens at Fort Gratiot was swapped with the "fixed varied with a flash" lens from the Pointe Aux Barques light.
The green lens came in 1933, when the fresnel was replaced with an aerobeacon. Perhaps the green light stands out from background lights?
