The war ended on November 11, 1918, and America's economic boom quickly faded. Factories began to ramp down production lines in the summer of 1918, leading to job losses and fewer opportunities for returning soldiers. This led to a short recession in 1918–19, followed by a stronger one in 1920–21
An example of a single-issue party would be: Prohibition party
Single issue party refers to a party that created in political landscape to fight only for one specific issue. Prohibition party could be considered as an example of single-issue party because it was created specifically to oppose the sales of alcohol related products.