May is Asian American and Pacific Islander Heritage Month (APAHM), celebrating the achievements and contributions of Asian Americans and Pacific Islanders in the United States. The month of 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. According to the U.S. Census, there are 18.5 million Americans who identify as Asian, Pacific Islander and/or Native Hawaiian. They represent many diverse cultures, languages, and customs that are unique to each community. Asian Americans have a high prevalence of chronic obstructive pulmonary disease, hepatitis B, HIV/AIDS, smoking, tuberculosis and liver disease. Some health conditions and risk factors that are prevalent among Native Hawaiians and Pacific Islanders are hepatitis B, HIV/AIDS, and tuberculosis.