The British Museum was established by an Act of Parliament on June 7, 1753. As a frequent visitor to that splendid place, Tory Historian can feel nothing but gratitude to the long-living Sir Hans Sloane (1660 - 1753) , physician, collector, naturalist and the man whose will led to the establishment to what must be the finest museum in the world. (TH is prepared to fight all comers on that subject.) Gratitude is also due to the Parliament of the day whose far-sightedness enabled the museum to come into existence.
Incidentally, Sir Hans seems to have been an excellent doctor as well:
An innovative doctor, Sloane promoted inoculation against smallpox, the use of quinine (a treatment for malaria) and the health-giving properties of drinking chocolate mixed with milk.By the time he died in Chelsea
his collection amounted to more than 71,000 objects. Chiefly natural history specimens, the collection also included:
23,000 coins and medals 50,000 books, prints and manuscripts a herbarium (a collection of dried plants) 1,125 'things relating to the customs of ancient times'.
That became the nucleus of the new museum.The British Museum opened to the public on 15 January 1759 . It was first housed in a seventeenth-century mansion, Montagu House, in Bloomsbury on the site of today's building. Entry was free and given to ‘all studious and curious Persons’.
With the exception of two World Wars, the Museum has remained open ever since, gradually increasing its opening hours and moving from an attendance of 5,000 per year to today's 6 million.
Indeed, that is likely to grow. 
For your consideration.