English Colonial period. During the American Revolutionary War, the valley was also known as the Hollow Way, where the main action of the Battle of Harlem Heights began under the command of General George Washington. During the War of 1812 the valley's southern ridges figured as the site of the Manhattanville Pass, whose defense fortifications and breastworks included Fort Laight and Blockhouse No. 4, which became the sites of Morningside Gardens Houses and PS 36, respectively. Manhattanville's early population was a diverse and eclectic mix of intermarried American patriots and British loyalists; at least one prominent former African slave trader (this seems to be a reference to Michael Hogan, whose wife was of mixed British and Indian ancestry, born in Bombay); slave owners and enslaved African-Americans; Quaker anti-slavery activists and free black abolitionists; tradesmen, poor laborers and wealthy industrialists. Many were affiliated with the same institutions, principally the historic New York City landmarked St. Mary's Protestant Episcopal Church, organized in 1823, which was the first Episcopal church to dissolve pew rent in 1831, and the Manhattanville Free School (established in 1827, later Public School No. 43) still at their original sites. Manhattanville's most prominent resident was industrialist Daniel F. Tiemann (1805–1899), owner of the D. F. Tiemann & Company Color Works, who was also Mayor of New York City from 1858 to 1859. The Tiemann laboratory and factory which was originally located on 23rd Street and Fourth Avenue in Gramercy, near Madison Square Park, relocated uptown to Manhattanville in 1832, in part due to an underground spring of running water at the new uptown location, which is today the site of 560 Riverside Drive. Immigration and urbanization According to Eric K. Washington, “With Manhattanville’s formation, the new village quickly became a significant suburban destination along the Bloomingdale Road [today’s 125th St.]... Manhattanville flourished naturally as a nexus of various transportation arteries.” In the late nineteenth century, Manhattanville experienced a development boom of residential buildings, churches, hospitals, institutional construction, and transportation made it a desirable location for the brewery business. Later noteworthy population changes occurred around the mid-19th century following the opening of the Hudson River Railroad in 1850, with an influx of mostly Catholic Irish (who established the Church of the Annunciation in 1854) and Germans (who established St. Joseph's Roman Catholic Church in 1860). After the American Civil War, the Jewish immigrant population that began to distinguish itself in