Tibbles played an important role in the trial of Standing Bear, a legal battle which led to the liberation of the Ponca tribe from the Indian territory in Oklahoma in the year 1879.

This landmark case led to important improvements in the civil rights of Native Americans throughout the country and opened the door to further advancement.

[1][3] Taken prisoner by pro-slavery forces, he was sentenced to be hanged but escaped, though he lost part of his ear to a musket ball.

[1] During this time, he joined the Union forces as a scout in the states of Kansas and Missouri, and was assigned to break up gangs of horse thieves.

[1] Of himself, Tibbles wrote that he was "Raised on the frontier and preferred not to be educated," and, "He carried perhaps the marks of more gunshot and other wounds… than any other one man in a thousand miles...

Although the Omaha tribe, who were closely related to the Ponca and spoke the same language, had given gave them 30 acres of good land, the government would not allow them to take it.

[1][3][6] General George Crook, who objected to his orders to arrest the group, met secretly with Tibbles in his office and implored him to take up their case, insisting that he was the only one who could save them.

[1] Through these efforts and the efforts of Susette Laflesche, a well-educated Omaha interpreter who raised awareness of the Ponca plight by speaking publicly to local church congregations,[8] they obtained pro-bono legal representation for Chief Standing Bear in court and raised national awareness of the case.

[9] Judge Elmer Dundy ruled in favor of Chief Standing Bear, concluding that American Indians did indeed have the rights of citizenship.

Once the trial of Chief Standing Bear was over, Thomas Tibbles would continue to campaign for equal treatment for Native Americans.

During the summer of 1879 until early September of the same year, he went on a speaking tour to Chicago and Boston raising awareness of the plight of the Poncas, in addition to the other tribes in the Nebraska territory, as well as lobbying for Native American citizenship.

Both Tibbles and his new wife would continue lecturing throughout 1882-83, and they successfully lobbied for Congress to grant the Omaha tribe permanent individual allotments, though some of them would be dissatisfied about the way the land was divided.

He also married his third and final wife, Ida Belle Riddle, in 1907 after the death of Susette ("Bright Eyes") LaFlesche.

He would continue his active involvement in the Populist movement, including editing other newspapers for the party, from 1905 to 1910; after which he returned once again to the Omaha World Herald until his retirement in 1928.