In 1919, he was brevetted lieutenant-colonel and received the distinguished service citation from General John Pershing for heroism in treating and evacuating wounded soldiers under fire.
[2] After the war, Mundy resumed his medical practice and entered politics by directing the campaign of his brother for city council.
He became the chair of the Luzerne County Democratic Committee which gave him control over patronage jobs.
In 1932, he was a delegate to the Chicago Democratic Convention and actively supported the nomination of Franklin Delano Roosevelt.
As a reward for that support, he was appointed collector of internal revenue for the Middle District of Pennsylvania.