Quick Answer: Were Tax Returns Always Due on April 15?Nope. Until 1955, returns were due on March 15. From 1913 to 1918, they were due even earlier, with taxpayers scrambling to meet a March 1 deadline.
In 1954, Congress changed the date to give IRS employees a break. Most returns were filed near the deadline, swamping agency employees. Lawmakers hoped a later deadline would encourage taxpayers to file earlier. Human nature being what it is, returns continued to flood the agency just before the new deadline. In recent years, about 20 percent of returns have been filed in the last week of the filing season.