Complex sentence: Isaac Thomas Hecker (December 18,1819-December 22,1888), American Roman Catholic priest, the founder of the Paulist Fathers, was born in New York City, of German immigrant parents.
Split into simpler sentences: Isaac Thomas Hecker (December 18,1819-December 22,1888), was an American Roman Catholic priest and the founder of the Paulist Fathers religious community. He was born in New York City, of German immigrant parents.