The British Museum was established in 1753 and was the first national public museum in the world. It was founded based on the collection of Sir Hans Sloane, which consisted of over 71,000 objects. The collection grew over the centuries to include artifacts from around the world and visitor numbers increased from 5,000 annually in the 1700s to over 6 million today. Major expansions and acquisitions in the 19th century led to the construction of the Museum's iconic quadrangle building. The 20th century saw a focus on education programs and gallery refurbishments to improve the visitor experience.