The month of May was chosen to commemorate Asian American and Pacific Islander Heritage Month as it remembers the migration of the first immigrants from Japan to the United States on May 7, 1843 and to celebrate the completion of the transcontinental railroad by over 20,000 Asian immigrants on May 10, 1869. But historical records show that the first Asian immigrants arrived in the United States in 1587 when Filipinos first began migrating to California. Immigrants continued to come from the Asian continent and the Pacific Islands through 1920 when the first Samoans were documented in Hawaii.