In 1978, a joint congressional resolution established Asian/Pacific American Heritage Week. The first 10 days of May were chosen to coincide with two important milestones in Asian/Pacific American history: the arrival in the United States of the first Japanese immigrants (May 7, 1843) and contributions of Chinese workers to the building of the transcontinental railroad completed May 10, 1869. In 1992, Congress expanded the observance to a monthlong celebration that is now known as Asian American and Pacific Islander Heritage Month.