Admittance to the collection was free, but visitors who arrived on foot were turned away; only those who could afford a carriage or riding horse were welcome.

He decided to exhibit the collection in London as a commercial venture, charging an entrance fee.

[2] Lever acquired a lease of Leicester House in 1774, converting the principal rooms on the first floor into a single large gallery running the length of the house, and opened his museum in February 1775, with around 25,000 exhibits (a small fraction of his collection) valued at over £40,000.

[4][5] The display included many natural and ethnographic items gathered by Captain James Cook on his voyages.

[6] The museum took its name from its supposedly universal coverage of natural history,[4] and was essentially a huge cabinet of curiosities.

[7] Among the objects displayed was the large Viking silver thistle brooch from the Penrith Hoard, discovered by a boy in Cumbria in 1785.

[4] It continued to be displayed at Leicester House until Lever's death in 1788, at a reduced entrance fee of one shilling.

[9] Parkinson also had George Shaw write an illustrated scientific work;[10] the artists involved included Philip Reinagle, Charles Reuben Ryley, William Skelton, Sarah Stone, and Sydenham Edwards.

Ellenor Fenn wrote A Short History of Insects (1796/7), which also served as a "pocket companion" for the museum.

One attempt, a proposed purchase by the government, was wrecked by the adverse opinion of Sir Joseph Banks.

Among the present collections of World Museum are 25 study skins (relaxed mounts) of 22 species recognized as having originated from the Leverian Sale.