The East Side is a large district of Buffalo, New York, and the city's physically largest neighborhood. It is bordered by Main Street to the north and west, I-190 and the Kaisertown neighborhood to the south, and the town of Cheektowaga to the east. Large, ornate 19th-century churches, most of them Roman Catholic, and modest 1+1ā2-story wood-frame cā¦The East Side is a large district of Buffalo, New York, and the city's physically largest neighborhood. It is bordered by Main Street to the north and west, I-190 and the Kaisertown neighborhood to the south, and the town of Cheektowaga to the east. Large, ornate 19th-century churches, most of them Roman Catholic, and modest 1+1ā2-story wood-frame cottages, often with progressively smaller rear additions that give a telescoping effect, characterize the district. The East Side was once the second largest Polish-American community in the United States. Jefferson Avenue, and the intersection of Broadway and Fillmore, serve as its most heavily used commercial districts.