The Croton Aqueduct is a historic water supply system that was built in the mid-19th century to provide fresh water to New York City. Completed in 1842, it stretches over 40 miles from the Croton River in Westchester County to the city, delivering water through a series of tunnels, bridges, and reservoirs. The aqueduct was a significant engineering achievement of its time, designed to meet the growing demands of the city's population. It played a crucial role in improving public health by supplying clean water, which helped reduce the spread of waterborne diseases in the rapidly expanding urban area.