In 1870, Barnum accepted an offer from William Cameron Coup to start a traveling circus. The so-named "P.T. Barnum's Grand Traveling Museum, Menagerie, Caravan, and Circus" opened in Brooklyn in 1871 and went on to gross $400,000 in its first year [source: Barnum-Museum.org]. It was the first circus to travel by train and featured acrobats, clowns and various performances; large exotic animals such as giraffes and elephants in addition to trained horses and dogs; and "human curiosities," such as little people, albinos and giants. Barnum famously called it "The Greatest Show on Earth," and that probably wasn't an exaggeration.
During the winter, Barnum housed his circus and animals in the Hippotheatron, on the site of what would later be Madison Square Garden. In 1872, yet another disastrous fire wreaked havoc in Barnum's life, destroying the Hippotheatron and killing the circus animals. The partners successfully regrouped, determined to outdo the rival circuses despite the setback.
The next year, while Barnum was visiting his friend John Fish in England, Charity died of heart failure. Barnum was supposedly too grief-stricken to return for her funeral. But the grief must've subsided quickly; he secretly married Fish's daughter, 22-year-old Nancy Fish, less than 14 weeks later. (They held a public wedding in the United States nine months after that.)
In 1875, Barnum took a break from traveling with the circus to successfully run for mayor of Bridgeport. He had become a teetotaler (after drinking heavily during his tour in Europe), and so he campaigned against allowing saloons to be open Sundays. He also fought for gas-lit streets and threatened that the city would take over the water company unless it improved standards. After his term expired as mayor, Barnum served in the Connecticut General Assembly for two more terms [source: Sullivan].
Barnum parted with Coup in 1876 and combined forces with the "European Menagerie and Circus." It wasn't until 1880 that he finally partnered with James A. Bailey for "P.T. Barnum's Great London Combined." The next year, he attained Jumbo, an elephant 11 feet tall and 6 tons in weight — the circus's biggest attraction until Jumbo's death in 1885 when he was struck by a train. In true Barnum style, however, he continued to display Jumbo's preserved hide and skeleton. That same year, Barnum and Bailey went their separate ways, but they would join again to become equal partners in 1887 for the "Barnum and Bailey Circus."
By 1890, the elderly Barnum was still going strong until he suffered a stroke during a performance. While Barnum was confined at home and knew he was near death, the New York Sun granted his request to publish his obituary early. The great entertainer died the next year.