It's really interesting that, at least at that time and in that place, there appeared to be more employment discrimination against Irish than African-Americans. I noticed that several of the job ads would accept "colored" applicants, but not Irish.
At the time, black people were stereotyped as servile and easily pressed to work, while the Irish were stereotyped as pugilistic, unreliable layabouts (and, to some, sinister Papists).
Edit: "that" -> "than".