Congress in 1978 passed a resolution creating Asian/Pacific American Heritage Week. It expanded the observance to a month (May) in 1992, timed to coincide with two important milestones in Asian/Pacific American history: arrival of the first Japanese immigrants in the United States (May 7, 1843) and completion of the transcontinental railroad on May 10, 1869 (the majority of workers who laid the tracks were Chinese immigrants).