Nursery Co., which eventually was relocated to Mt. Hope Avenue, across from Mount Hope Cemetery. James Vick and Joseph Harris also start their own nursery businesses. The population in 1830 was only 9,207, but it still ranked as the 25th largest city in the United States. In 1840, the population and rank were 20,191 and 19th, respectively. In 1842, the original aqueduct over the Genesee River was replaced with a better one slightly south of the first one. This latter aqueduct now supports Broad Street. By 1850, the population reached 36,000, making it the 21st largest city in the United States. Westward expansion had moved the focus of farming to the Great Plains and Rochester's importance as the center for flour milling had declined. Several seed companies in Rochester had grown to become the largest in the world, with Ellwanger & Barry Nursery Co. the largest. Rochester's nickname was changed from the Flour City to the Flower City. In 1850, the University of Rochester was founded in the U. S. Hotel on Buffalo St, and affiliated with the Baptist Church. Two four-year courses were offered. In 1851, due to Rochester and Monroe County's tremendous growth, a new three-story county courthouse in the Greek Revival style was constructed. It was built from brick manufactured at Cobb's Hill by Gideon Cobb, and cost $76,000. Rochester abolitionism Rochester takes pride today in its role as the last Underground Railroad stop for fugitive slaves before taking a boat for Canada, across Lake Ontario. It was the home for many years of abolitionist Frederick Douglass, a formerly enslaved African American, who in 1847 commenced publishing an abolitionist newspaper, The North Star, in Rochester. The paper's name refers to fugitive slaves' destination: north. The Underground Railroad In the years leading up to the Civil War, numerous locations in the Rochester area were used as safe houses to shelter fugitive slaves before they were placed on board boats (often on the Genesee River) for transport to Canada. The route was part of the famous Underground Railroad. Other "stations" were located in the areas surrounding Rochester, including Brighton, Pittsford, Mendon, and Webster. A station in North Chili, just west of Rochester, run by abolitionist Methodists was an important site in the formation of the Free Methodist Church, which was formed in 1860. The denomination's first college, Roberts Wesleyan College, was built on the site. One contemporary described the