Fort Lyon (Cow Island, Casco Bay, Maine)

Cow Island, Casco Bay · Maine · World War I, World War II

Quick BriefBuilt on 22 acres of Cow Island and completed by 1909, Fort Lyon was a sub-post in Portland Harbor's coastal defenses, equipped with Battery Abbot's three-inch guns and a battery of six-inch guns named for Union officer George Dashiell Bayard. About 100 soldiers garrisoned the fort during both World Wars, though it saw no combat.

Endicott SystemCoastal defense

History & Significance

Fort Lyon was constructed on Cow Island following the 1873 acquisition of the island to provide greater coverage of the Hussey Sound approach to Portland Harbor, complementing Fort McKinley on Great Diamond Island. Work began in 1900 with initial clearing; foundations for three-inch guns were poured in 1903, with the guns mounted in 1909 as Battery Abbot, named for Union officer Edward Stanley Abbot who died of wounds at Gettysburg.

The Army also approved a second battery of three six-inch disappearing guns, emplaced on the southeastern side and named for Union General George Dashiell Bayard, who fell at Fredericksburg. During World War I, the fort's guns were partially removed; the six-inch guns were mounted on field carriages and shipped to France, later returning to the United States.

In World War II, Fort Lyon was garrisoned with a coastal artillery company defending Hussey Sound, with antisubmarine netting stretching across the channel. By 1943, most guns had been scrapped, leaving only three-inch guns at Battery Abbot. After World War II, the Army sold Cow Island to private owners.