In 1964 he returned to St. Aloysius and remained there for the rest of his life, living at Gonzaga College High School and serving the poor.
The McKenna Center, a local shelter and soup kitchen for homeless men, located under the Great Church of St. Aloysius, was named after him in 1982.
The Father McKenna Center is still located in the basement of Saint Aloysius Catholic Church at 900 North Capitol Street NW in Washington, DC.
The McKenna Center exists to meet the needs of the poor and homeless who reside in one of Washington's poorest neighborhoods despite being in the shadow of the US Capitol Building.
Each day, the McKenna Center fulfills the Gospel instruction to “feed the hungry, shelter the homeless and clothe the naked”.