Mount Pleasant has deep American roots going back to the Revolutionary War, when local tenant farmers filled the ranks of General Washington's Continental army. For years, travel to New York City was difficult, until the arrival of the railroad in 1846 allowed easy transportation to lower Manhattan. In 1893, John D. Rockefeller Sr. began buying land in Pocantico and built his classic Georgian mansion. The massive Kensico Dam in Valhalla was completed in 1917 to satisfy the growing thirst of New York City. In 1927, Rose Hawthorne, the daughter of writer Nathaniel Hawthorne, completed the...