Asian American and Pacific Islander Heritage Month (AAPI), celebrated in May, recognizes the contributions and influence of Asian Americans and Pacific Islander Americans to the history, culture, and achievements of the United States. May was chosen to commemorate the immigration of the first Japanese to the United States on May 7, 1843, and to mark the anniversary of the completion of the transcontinental railroad on May 10, 1869. The majority of the workers who laid the tracks were Chinese immigrants.