Asian Pacific American Heritage Month is celebrated in May to honor the contributions and achievements of individuals from the Asian and Pacific Islander communities in the United States. This month recognizes the rich history, culture, and traditions of these diverse groups, highlighting their impact on American society. The observance began as a week-long celebration in 1977 and was later expanded to a month in 1990. It was chosen to commemorate the arrival of the first Japanese immigrants in the U.S. in May 1843 and the completion of the Transcontinental Railroad in May 1869, which was largely built by Chinese laborers.