The War of 1812 was the last time that a foreign army invaded the United States. American strategists understood that it was only a matter of time before the British naval forces attempted to take control of New Orleans. This access would have granted them unprecedented control of shipping along the Mississippi River and into the heart of the Unites States. In December of 1814 U.S. Navy Commodore Daniel Patterson, commanding the Naval Station at New Orleans, received a letter from Pensacola informing him that British warships were operating in the region. Patterson ordered five U.S. gunboats, one tender-ship, and a dispatch schooner to Pass Christian and Pass Marianne to observe British vessels operating within the Mississippi Sound.
Following these orders, two U.S. gunboats were sent to Dauphin Island, Alabama to observe British forces and report back, while three other gunboats patrolled the Mississippi Sound. While anchored within Dauphin Island just outside of Mobile Bay, the two U.S. gunboats spotted a pair of British warships sailing to the west towards Mississippi. While keeping sight of the British warships, the commanders of the U.S. gunboats sailed inside (on the northern coastal side) of the barrier islands in waters too shallow for British warships to operate, while using the barrier islands as effective cover for the American ships.
The five American ships rejoined forces offshore Biloxi and continued together west toward Lake Borgne. As the small U.S. fleet reached the western tip of Cat Island, they were surprised to discover that the British fleet (initially 2 ships) had increased so large as to be insurmountable given their current capabilities and number.
This British naval force had grown overnight to more than twelve hundred troops and forty-five launches and barges with forty-three cannon. The small American fleet continued westward to Pass Marianne, offshore in the mouth of Bay St. Louis, between the towns of Pass Christian and Bay St. Louis, where they anchored and received provisions from the armory at Bay St. Louis.
Fearing that military supplies stored in Bay St. Louis would fall into British hands, the U.S. commander sent the U.S. Schooner Seahorse into the bay on orders to remove or destroy the stored supplies. The British commander sent three ships in an attempt to intercept the USS Seahorse.
An elderly woman from Natchez, who was visiting the city, (Mrs. Isabella Hutchins Claiborne) while watching the approach of the British ships in pursuit of the USS Seahorse was quoted as saying,
“Will no one fire a shot in defense of our country?”
Following this query, a bystander took the opportunity to light the fuse of a nearby cannon. The coastal cannon fire struck close to the approaching British fleet, whose commanders assumed there were strong American defense forces in the bay. The British fleet retaliated by returning fire on both the city and the USS Seahorse. Attacked by British bombardment, the USS Seahorse managed to hold out for a short time with support from the Bay St Louis shore battery. The initial volley from the Seahorse repelled the three British ships which withdrew shortly, only to be reinforced by four other British ships. This force of seven British ships spurred the American commander to destroy both the Military Supplies on shore as well as scuttle the USS Seahorse inside Bay St Louis.
The remaining American vessels moved west into Lake Borgne headed toward the Rigolets and Fort Petite Coquille (a defensive battery now occupied by Fort McComb) located on the east end of Lake Pontchartrain in the Rigolets.
Unfortunately, the winds were against the American Ships, including the USS Alligator, which were forced aground in the channel of Malheureaux Island on Dec. 14.
The US Forces lashed the remaining vessels together across the channel near Malheureux Island and made their final stand at that location. This further stalled British progress in their approach to New Orleans. When the tides changed, and the American Vessels began to drift the British were able to capture the remaining U.S. Ships and gain further access to the Rigolets and the east end of Lake Pontchartrain
Though initially considered a military defeat, these were later considered successes in that the Americans were able to repel a British advance force, killing or wounding nearly every officer and sinking two of the seven advance boats before falling to the superior numbers and equipment of the British Navy. In the end, there were six American sailors killed and thirty-five wounded while the British lost seventeen and had an additional ninety-four wounded.
At first glance, the battles of Bay of St. Louis and Lake Borgne may appear to be insignificant in the overall outcome of the War of 1812, however the two small actions delayed the British fleet on its mission into New Orleans for the Battle of New Orleans, thus giving Andrew Jackson and his forces time to establish fortifications at the Chalmette Battlefield for the final decisive military action in the War of 1812.