<human>:  Why did so many Chinese people migrate to the United States in the late 19th century?
<bot>: The Chinese were primarily escaping from the Boxer Rebellion in China. The Boxer Rebellion was a war between the Chinese government and a group of anti-foreign Boxers. The Boxers were a group of people who were opposed to the presence of foreign powers in China. The Boxer Rebellion began in 1899 and lasted until 1901.