Race relations of a different kind led to internal conflict in the West. The Chinese were the first Asians to arrive in large numbers to the United States in the nineteenth century. By 1849, tens of thousands had left China from Hong Kong to migrate to countries throughout the world, including the sugar plantations of Hawaii and to the Pacific Northwest for the Gold Rush. Others came to America to labor on the railroads, farms, lumber mills, hop fields, coal mines, and salmon canneries. Thousands of Chinese "coolies", as they were called, were recruited especially to help build the Northern Pacific Railroad which spanned the United States. However, the white settlers in the West soon began to despise and resent the Asian newcomers. In the South, the Delta Chinese arrived in the years immediately after the Civil War to work on the cotton plantations and then opened groceries. Being neither black nor white in the Jim Crow South, the Chinese navigated a confusing, sometimes inconsistent set of racism, exclusion, segregated schools, laws and social mores. The Chinese were denied equal education and minimal wages, were banned from testifying in court, were forced to live in ethnic enclaves away from the rest of society, and were victims of riots and anti-Asian violence, including the Chinese Massacre of Los Angeles in 1871. Hatred against the Chinese reached such a boiling point that in 1882, Congress passed The Chinese Exclusion Act, which prohibited all immigration of admission of unskilled Chinese laborers for ten years, alongside a ban against "lunatics, idiots, convicts, persons likely to become public charges." The Act was renewed in 1892 and the ban made "permanent" in 1902.
There's more about this, especially in the post-Civil War era. For many decades protection of white labor as endorsed by Abraham Lincoln continued to be a major campaign issue.