The National Council of Young Men's Christian Associations of the United States of America (known as YMCA of the USA) is part of the worldwide youth organization YMCA. It has 2,700 separate organizations with 10,000 branches working with 21 million men, women and children, to "strengthen communities through youth development, healthy living and social responsibility." It employs 19,000 staff and is supported by 600,000 volunteers, and YMCA branches have about 10,000 service locations. The first YMCA in the United States opened on December 29, 1851, in Boston, Massachusetts. It was founded in 1851 by Captain Thomas Valentine Sullivan (1800–59), an American seaman and missionary.