Harry Stewart New was born in Indianapolis, Indiana, on December 31, 1858, and attended Indianapolis public schools and Butler University. New worked at the Indianapolis Journal newspaper and later became its editor and publisher. During the Spanish-American War, New served as a captain in the U.S. Army.

Involved in Republican Party politics, New was a delegate to the Republican National Conventions in 1896, 1912, 1920, and 1924. He served on the Republican National Committee from 1900 to 1912 and was its chair from 1907 to 1908. Elected to public office as Indiana state senator in 1896, New served in that capacity for two years (1897-1899). He was elected as a U.S. senator from Indiana, serving from 1917 to 1923.

President Warren G. Harding appointed New postmaster general in 1923. Following Harding's death, President Calvin Coolidge reappointed New to that post, and he stayed on until 1929. New died on May 9, 1937.