Complex sentence: It was from this building that Rev. Vassani and Father Godfrey Schilling began to plan to build a "Holy Land in America" and a Holy Sepulchre, which they envisioned crowning a high hill on Staten Island, overlooking the entrance to New York's harbor.
Split into simpler sentences: It was from this location that Rev. Vassani and Father Godfrey Schilling began to plan to build a "Holy Land in America" and a Holy Sepulchre. They envisioned building on a high hill on Staten Island, overlooking the entrance to New York's harbor.