Thread by @pptsapper

The pre-WWII National Guard is a complex institution to look at. On one hand, as this thread points out, there were glaring readiness issues. OTOH, the NG also container some superb combat leaders who cut their teeth on the Western Front & trained their troops in what NOT to do

https://twitter.com/usacac/status/1384505143337439237

In addition, this thread just talks about the combat divisions, because that's what's pertinent to the GHQ Maneuvers. But something else happens in 1940: all coast artillery corps regiments are fully activated for federal service, which they'll be on thru the duration of the war

What's the coast artillery, you ask?

Big. Ass. Guns. Like this monster 12" disappearing gun, a staple of the harbor defenses, along with 10" rifles and mortars, and 6" and 3" guns, 155mm mobile guns, AAA guns, and searchlights.

These monsters were merely the protection for the real harbor defenses. The fields of sea mines laid out as obstacles to vessels and subs. The anti-sub nets. The hydrophones (underwater mics) and naval loops (submerged electrical cables that changed current if a ship passed)

Yes, the Army had boats. The mine-planting service is one reason we have warrant officers, because the Army needed subject matter experts to run these boats. The CAC was a highly technical branch, and due to force structure cuts, was mainly composed of National Guard units

In September of 1940, FDR began activating the CAC NG units, ordering them to their duty stations - which for most, weren't far from their armories or where they lived. The CAC homeland defense mission fit perfectly for the NG - hence why it had been given to them

As it turned out, this would send some CAC units VERY far from home. Like New Mexico's 200th Coast Artillery Regiment, that would be sent to the Philippines - and see the war far sooner than any of them expected. Many died in the Bataan Death March.

But for the most part, the CAC units remained in their harbor defenses throughout the war - altho many of the original members of units were pulled to fill artillery or AAA units in the ETO or PTO, precisely because they had the experience.

By 1944, it was evident that the harbor defenses of the US were not going to be tested by enemy battleships, so units and fortifications underwent a redesign. By 1946, the CAC had been inactivated entirely & its units converted to anti-air: the new threat would come from the sky

DAMMIT. 1941, not 1940. I keep getting my years mixed up. From January of 1941 to the end of the year, FDR and the War Dept activated harbor defense CAC units, and anti-aircraft CAC units