Comintern Artillery Hauler (Soviet Union)

Shortly after WWI most developed countries began to abandon hauling their artillery by horse teams in favor of mechanical transportation. Details 

A-19 122mm Cannon (Soviet Union)

Before WW1, heavy artillery was usually used to siege or defend a fortress. Because of its immobility it was considered useless for field battles. Light field cannons with higher rates of fire were more efficient against enemy infantry, cavalry and artillery. Details 

M3-A1 Halftrack Armored Personnel Carrier (U.S.)

Once the war in Europe began, The U.S. began to analyze the both the strategies and the vehicles that were being used. They were especially impressed with the use of half-tracked personnel carriers and artillery haulers that the Germans were using. Details