In 1831, at a time when the city was quickly expanding and the surrounding area was still sparsely developed, Samuel Ruggles, one of the founders of the Bank of Commerce and the developer of Gramercy Park to the northeast, convinced the city to rename the area as "Union Square". In doing so, Ruggles also got the city to enlarge the commons to 17th Street on the north and extend the axis of University Place to form the square's west side, thus turning the common from a triangular to a rectangular area. By 1832, the area had been renamed Union Square. Ruggles obtained a fifty-year lease on most of the surrounding lots from 15th to 19th Streets, where he built sidewalks and curbs. In 1834, he convinced the Board of Aldermen to enclose and grade the square, then sold most of his leases and in 1839 built a four-story house facing the east side of the Square. The park at Union Square was completed and opened in July 1839.