In the late 1700's the US began a coastal defense system to protect ports and strategic points, and Texas, which became a State in 1845, included several Gulf Coast sites that later proved important in US military engagements. In March 1941, before the US entered World War II, the War Department created the Southern Defense Command as part of its national defense system under Lt. Gen. Walter Krueger, covering the Southern US coastline from North Carolina to Brownsville. After the Japanese bombed Pearl Harbor on Dec. 7, 1941, the US increased defense efforts along the Texas coast, including military bases and key wartime industries. A month later, in what may have been a false alarm, a German U-boat was reported just miles off the entrance to the Aransas Pass, and the Southern Defense Command sent a temporary field artillery battery of the 2nd Infantry Division to Mustang Island, where it set up 105 MM howitzers. In April 1942, Battery E of the 50th Coast Artillery Regiment relieved those troops and remained until October 1942, beginning the emplacement of two French-designed 155-MM GPF guns on Panama mounts and the construction of timber magazines, a commander station, searchlights, and a camp for 360 men. Battery G of the 20th Coast Artillery Regiment, stationed there from October 1942 to March 1944, and Battery E of the 20th Coast Artillery Regiment, there from March to July 1944, completed the work, while the US Navy operated a harbor entrance control post in conjunction with the Coast Artillery. Officially designated temporary harbor defenses at Aransas Pass, this coastal defense complex just south of the South Jetty closed in July 1944 after enemy naval threats in the Gulf were no longer a concern.
