Both were widely deployed in the United States postwar as the Cold War presented a perceived threat from Soviet bombers.

There had been several upgrades to the weapon over its history, including the experimental T8 and T9 versions developed in the early 1930s, that were intended to enter service later in that decade.

A few hundred M1s were completed when several improvements were added to produce the 90 mm M1A1, which entered production in late 1940, and was accepted as the standard on 22 May 1941.

Since national arsenals had limited capacity, production of first 300 gun mounts was contracted to Allis-Chalmers in November 1940, with the first unit shipped in September 1941.

[5] The M1A1 included an improved mount and spring-rammer on the breech, with the result that firing rates went up to 20 rounds per minute.

Like the German 88 and the British QF 3.7 inch AA gun, the M1A1 was used against tanks in combat but, unlike the others, it could not be depressed to fire against them.

In 1944, the system was upgraded with the addition of the SCR-584 microwave radar, which was accurate to about 0.06 degrees (1 mil) and also provided automatic tracking.

[7] However, both the muzzle velocity of the standard M3 gun and the quality of the steel used in the M82 APC (armor-piercing capped) shot, while comparable to the 8.8 cm KwK 36 L/56 mounted on the Tiger I, were inferior to the Tiger II's KwK 43 L/71 8.8 cm main gun firing its standard APCBC (armor-piercing capped ballistic cap) shot used by German forces, with the result that the former's penetration fell far short of the standard projectile fired by that German tank.

[7][8] The HVAP could compete with the KwK 43's penetration performance when firing standard APCBC, but tungsten ammunition was always in short supply.

Its gun was fired in anger on only one occasion, on 4 April 1945, where it engaged and destroyed a German armored vehicle, probably a Tiger I or Panther, at a range of 4,500 ft (1,400 m) during the fighting along the Weser River.

[13] According to the memoirs of John P. Irwin, it knocked out a King Tiger in Dessau as well as a Panzer IV and a Panther.

In the post-World War II era, development of the T15 continued redesignated as the T54, which used a slightly shorter and fatter propellent casing than that of the T15E1.

[15] The lightweight variant of the T119, designated as the T139 and standardized as the 90 mm gun M41, equipped the M48 Patton tanks used in the Vietnam War.

This gun was found to be inadequate and incapable of penetrating modern armor, requiring a stop gap of HEAT-FS shells to be utilized until the 105mm L7 derivative could become more prevalent.

During World War II the Coast Artillery Corps adopted the 90 mm M1 to supplement or replace aging three-inch guns in harbor defense commands in CONUS and US territories.

Emplacements for at least 90 batteries of two fixed guns each, plus mobile weapons, were constructed in CONUS, Panama, Alaska, Hawaii, Puerto Rico, and elsewhere in 1943.