He received his early education at The Albany Academy, and entered the college of Chambly in Quebec, Canada, at age fourteen.

After three years at Chambly, he returned to the United States and enrolled at Mount St. Mary's Seminary in Emmitsburg, Maryland.

[3] He then served as a curate at St. John's Church in Utica[4] until 1841, when he was transferred to St. Patrick's Cathedral in New York City.

[5] On June 19, 1853, Loughlin was appointed the first Bishop of the newly erected Diocese of Brooklyn by Pope Pius IX.

[3] He, along with James Roosevelt Bayley, first Bishop of Newark, received their episcopal consecration on the following October 30 from Archbishop Gaetano Bedini, with Bishops John McCloskey and Louis Amadeus Rappe serving as co-consecrators.