In 1977, U.S. Representatives Norman Mineta and Frank Horton introduced legislation to designate 10 days in May as Pacific/Asian American Heritage Week. U.S. Senators Daniel Inouye and Spark Matsunaga proposed supporting legislation in the Senate. The lawmakers chose May to mark two historical events. On May 7, 1843, the first Japanese immigrant arrived in the United States. More than two decades later, on May 10, 1869, the golden spike was driven into the First Transcontinental Railroad, which was completed using Chinese labor.

President Jimmy Carter signed a joint resolution for the celebration on October 5, 1978.  In 1990, George H.W. Bush signed a bill passed by Congress to extend Asian-American Heritage Week to a month, and May was officially designated as Asian-Pacific American Heritage Month two years later.