"There was what they called an Irish town near the old St Patrick's church, and that was on Harrisburg. In the 1880's there was the first St Patrick's Day parade and it started from that church and ended up in Market Square."
Many of the immigrants went to work in Houston's shipping industry. Later generations of Irish-Americans found success in the oil and gas business. Gallagher points to oilman Glenn McCarthy who founded the Shamrock Hotel.
"And that hotel as you'll remember ran from 1949 to 1986. So the Irish have been very involved in taking the money they've earned in other industries, for example the oil and gas industry, and then building the city around that."
The University of St Thomas was founded by Irish priests in 1947. Since 2003 the school has been home to the Center for Irish Studies which offers classes and other activities highlighting the history and culture of Ireland.
Photos from the Center for Irish Studies, University of St. Thomas.