The 4th Army Corps Patch was worn from: 26 January 1927 to late 1991 The 4th Army was activated August 1932 in Omaha, Nebraska. As a training army, The 4th Army prepared and equipped about half the combat troops sent overseas during World War II. For the 4th Army the cloverleaf on the insignia signifies the numerical designation of the army, while the colors are those traditionally associated with armies.