The Four Corners Historic District is the intersection of Broad and Market Streets in Newark, New Jersey. It is the site of the city's earliest settlement and the heart of Downtown Newark that at one time was considered the busiest intersection in the United States. The area that radiates twenty-two square blocks from the crossroads is a state and federal historic distriā¦The Four Corners Historic District is the intersection of Broad and Market Streets in Newark, New Jersey. It is the site of the city's earliest settlement and the heart of Downtown Newark that at one time was considered the busiest intersection in the United States. The area that radiates twenty-two square blocks from the crossroads is a state and federal historic district.