May is Asian Pacific American Heritage Month - a celebration of Asian and Pacific Islanders in the United States. Asian Pacific American Heritage Month originated in a congressional bill put forward by legislators. In June 1977, Representatives Frank Horton of New York and Norman Y. Mineta of California introduced a House resolution which called upon the president to proclaim the first ten days of May as Asian/Pacific Heritage Week. The following month, Senators Daniel Inouye and Spark Matsunaga introduced a similar bill in the Senate. Both were passed.
The proclamation of Asian/Pacific Week had to be brought forward each year because a Joint Resolution did not contain an annual designation. On October 5, 1978, President Jimmy Carter signed the Joint Resolution. In May 1990, the holiday was expanded further when President George H.W. Bush designated May to be Asian Pacific American Heritage Month. May was chosen to commemorate the immigration of the first Japanese immigrants to the United States in 1843.
(Source: Ricco Villanueva Siasoco)