The YMCA of Greater Boston, the first YMCA in America, began as a single site on December 29, 1851. Now one of the largest urban YMCAs in the county, the Greater Boston Y has over 36 branches and program centers serving 70,000 men, women and children in over 40 eastern Massachusetts communities. The first fifty years of the YMCA of Greater Boston included the founding of Northeastern University, the development of the first gym in the country on Tremont Street, and the establishment of Sandy Island Camp for Families in New Hampshire.