John Francis Campion (December 1849 – July 17, 1916) was a wealthy Canadian-American who made his fortune in mining and sugar production.

Campion ran away from school as a teen to join the Union Navy during the American Civil War.

He was a co-founder of what is now called the Denver Museum of Nature and Science and was president of the board of trustees until his death in 1916.

[5] Campion ran away from school at the age of 16 and joined the United States Navy during the Civil War.

[5] Campion began his service as assistant quartermaster on the USS Dolphin, which met General William Tecumseh Sherman's army and delivered dispatches at Savannah, Georgia, at the conclusion of Sherman's March to the Sea.

[5] John bought the Pioche-Phoenix silver mine in Pioche, Nevada, after he moved to the area with his brother and father.

[2][5] In 1878, Campion was elected a member of the parliament of Prince Edward Island for a one-year term.

Campion attracted investors because of his thorough knowledge of geology of the Leadville area, that enabled him to find large veins and predict the direction of ore deposits.

Ibex owned the Little Jonny Mine, where dolomite sand had filled any shafts that were dug and was on the verge of closing.

[5] Campion hired Brown to solve the problem, which he did by adding more timbering and inserting bales of hay to avoid collapse.

[5] The firm paid out $1 million (equivalent to $33,911,111 in 2023) in annual dividends to its stockholders beginning in 1894.

[5][6] His big gold strike at the Little Jonny Mine made him and his partners rich.

At the time, it was one of the few houses in the city to have electricity, which ran off its own onsite power plant.

[5] Nellie was mentioned in the Colorado representative women of 1914: A very beautiful woman, a gracious hostess of many brilliant social functions, and a fine mother, whose charming personality has made her well beloved, both in her beautiful home and in social life.

[6] His biography on their website states: John F. Campion's energy, intelligence, and drive were key factors in the development of the mining industry in Leadville, Colorado.

Widely known as "Leadville Johnny," he built a fortune in mining, was successful in a variety of other businesses, and contributed greatly to cultural activity in Colorado.