Chinese immigration to the United States sharply increased O in the 1820s.
O in the 1850s.
in the 1980s.
in the 1910s.

The history of Chinese Americans or the history of ethnic Chinese in the United States includes three major waves of Chinese immigration to the United States, beginning in the 19th century. Chinese immigrants in the 19th century worked as laborers, particularly on transcontinental railroads such as the Central Pacific Railroad.They also worked as laborers in

Explanation:

new evidence is discovered.

oversights and errors are corrected,

new technology is applied to evidence.