Throughout the interwar period the US produced only a few hundred tanks. From the end of World War I to 1935, only 15 tanks were produced. Most were derivatives or foreign designs or very poor quality private designs. The Christie designs were among the few bright spots, but the US Army acquired only three Christies and did not pursue the idea any further. Budget limitations and the low priority given to the Army meant that there were few resources for building tanks. The US Army instead developed and tested tank components such as suspensions, tracks, and transmissions. This work paid off when production needed to be initiated upon the outbreak of war.