[6] Its discovery was catalyzed by the announcement of the excavation of a large thigh bone (unrelated to Dippy) by William Harlow Reed near Medicine Bow, Wyoming in December 1898.

[7] On a return trip financed by Carnegie, Reed excavated Sheep Creek Quarry D in which he found the first part of Dippy's skeleton, a toe bone, on July 4, 1899.

[8] Its discovery on Independence Day, and its use in American diplomacy via Carnegie's international donations of replicas, led to its being nicknamed the "star-spangled dinosaur".

[11][12] The skeleton was found in the upper 10 metres (33 ft) of the Talking Rock facies of the Brushy Basin Member of the Morrison Formation, in Albany County, Wyoming.

[19][20] His great-grandson, William Thomson, was quoted in 2019 explaining the donations: "By gifting copies to the heads of state of seven other countries as well as the UK, Carnegie hoped to demonstrate through mutual interest in scientific discoveries that nations have more in common than what separates them.

[22] The 292 cast pieces of the skeleton were sent to London in 36 crates, and the 25.6 metres (84 ft) long exhibit was unveiled on May 12, 1905, to great public and media interest, with speeches from the museum director Professor Ray Lankester, Andrew Carnegie, Lord Avebury on behalf of the trustees, the director of the Carnegie Museum William Jacob Holland, and finally the geologist Sir Archibald Geikie.

[25] Dippy replaced a mounted African elephant, nicknamed George, which had been on display as the central exhibit in the main hall since 1907, with various other animal specimens.

After 112 years on display at the museum, the dinosaur replica was removed in early 2017 to be replaced by the 25 m (82 ft) long skeleton of a young blue whale, dubbed "Hope".

Holland noted a poem which had become popular among college students:[23][34] Crowned heads of Europe All make a royal fuss Over Uncle Andy And his old diplodocus.