Massachusetts General Hospital (MGH) in Boston is a premier teaching hospital affiliated with Harvard Medical School, housing the world's largest hospital-based research program with an annual budget exceeding $1.2 billion. Founded in 1811 and designed by architect Charles Bulfinch, it is the third-oldest general hospital in the United States, originally established to care for the poor. MGH made medical history in October 1846 when dentist William T.G. Morton and surgeon John Collins Warren performed the first public demonstration of inhaled ether anesthesia in the hospital's famous Ether Dome, a breakthrough that rapidly spread worldwide. The hospital has pioneered numerous innovations, including the first American hospital social workers and the development of the MUMPS programming language in the 1960s, which became vital for medical databases and patient records. Today, with 999 beds, MGH is a founding member of Mass General Brigham, the largest healthcare provider in Massachusetts, and continues to be a leader in clinical care and cutting-edge research.