Why did cities pave streets sanitize water and create public transportation systems between 1865 and 1920?

Between 1865 and 1920, cities paved streets, sanitized water, and developed public transportation systems primarily to address the rapid urbanization and population growth resulting from industrialization. These improvements aimed to enhance public health by reducing disease transmission, particularly from contaminated water, and to alleviate traffic congestion caused by increased mobility. Additionally, creating efficient public transportation systems facilitated access to jobs and services, fostering economic growth and improving the overall quality of urban life. These measures were essential in managing the challenges of modern urban living.