Speaking of WWII, on November 1, 1941, President Franking D. Roosevelt signed an executive order reassigning the service’s duties from the Treasury Department to the Navy a full five weeks prior to the Japanese attack on Pearl Harbor.
In all, 214,000 personnel served in the Coast Guard during WWII in a wide mix of missions.
The most high-profile fighting units in the service were its cutters and patrol boats, which sailed off to escort convoys against U-boats and slug it out on the beachline in amphibious assaults from North Africa and Guadalcanal to Normandy and Okinawa.
In addition to the 1,677 Coast Guard-flagged craft in active service at the end of the war, 56,000 Coast Guardsmen manned 326 Navy ships – including 76 landing ships, 21 cargo and attack-cargo ships, 75 frigates, and 31 transports – as well as 254 Army vessels.
To patrol 3,700 miles of American beaches for saboteurs landing from the sea, a scratch force of 24,000 officers and men, assisted by over 2,000 sentry dogs and nearly 3,000 horses, was built from the ground up almost overnight. These men carried M1903 Springfields, M1911 .45 ACP sidearms, and a mix of shotguns and submachine guns, with the Reising being one of the more popular.
At its peak strength on September 1, 1945, the Coast Guard totaled 170,480, including 9,624 uniformed women serving in the SPARS.
Some 125,000 personnel served in the Coast Guard's Temporary Reserve during the conflict, the latter manning the myriad “Corsair Fleet” of 2,998 converted motor and sail craft used for local patrol that had been acquired through purchase, charter, or gift, principally to combat the submarine menace along the coasts. These ships, dubbed the Hooligan Navy, were armed with small arms and obsolete guns, such as slow-to-load 37mm and 57mm deck guns leftover from chasing bootleggers during Prohibition.
Some 28 USCG-manned vessels were lost during WWII, adding 572 Coast Guardsmen to the massive butcher’s bill of the conflict.