The front porch provided a shady spot that bridged the public realm of the sidewalk and the private realm inside. From the porch, people could visit with neighbors strolling by. In a time before television, this provided contact with the outside world and a sense of community. Lots were often narrower, with houses closer together and pulled nearer the sidewalk. This allowed more houses to be fitted into a block.
Urban planners measure density in dwelling units per acre or in people per square mile.
But, back then, we kids measured density in the number of other kids in the neighborhood and the time it took to get to school. It was this higher density that allowed a neighborhood to have stores and schools. Higher density encouraged walking, made public transportation both practical for the rider and economically feasible for the municipality, and encouraged neighborhoods. Air conditioning and television took people off their front porches. The automobile made it just as easy to drive to the new mall out on the edge of town as to walk to the corner store.