St. Teresa of Avila, the substantial parish church at Sterling and Classon, is older than I thought. The parish was established in 1874, and the sanctuary itself dates from the same year (great old postcard here). Today, the building blends fairly seamlessly into the rest of the neighborhood, but it must have been visible for miles when it was built, an era when Charles Lewis Fussell was painting images of the neighborhood like this one and this one. What little history I could find of 19th century Crown Heights suggests that development kicked off in the 1880s (though I'm sure there's more to the story), so perhaps the establishment of this sturdy church was a harbinger of urbanization for the area.
Today, St. Teresa's offers Sunday Mass in three languages (English, Spanish, and Creole). The school across the street was originally St. Teresa's High, but that school closed in 2002 and was replaced by Brooklyn Jesuit Prep, a middle school. As for St. Teresa herself, she was a 16th century Spanish nun.