Why do Americans discriminate against Irish people?

Because Ireland was in the midst of an American immigration frenzy, many Irish people fled to Amei, so the Yankees had to give them places, and capable Irish people would compete with them for jobs. Moreover, during the pioneering period in the west, the Americans used many Irish workers to build railways for them, and many Irish people were exhausted on the west bank of the Mississippi River. This can also be seen from the side that early Americans discriminated against Irish people very much, but we should not expect Americans to treat people with red hair and straight hair equally in racial identity.