Why are people building tall and narrow structures in the United States? [origin

People across the United States are putting up tall and narrow structures to help a little bird called the chimney swift. They hope the birds will use these structures as nesting areas and resting places. Chimney swift’ s numbers are decreasing as the shape and design of the nation’ s buildings change. People are tearing down old factory buildings and schools. Many of these structures have chimneys.