In the 1920s he successfully sued the federal government in the US Court of Claims, to recover monies illegally obtained from tribal resources.

Prior to his election as governor, he had served as the superintendent of Bloomfield Academy, a Chickasaw girls' boarding school.

President Theodore Roosevelt appointed him as Governor of the Chickasaw after the Dawes Act changed how tribal lands were allocated and regulated in Indian Territory in an effort to push assimilation and prepare for statehood.

[5] Although his political critics claimed that he lived lavishly at tribal expense and indicted him in 1905, Johnston was acquitted of the charge.

[6] In 1897, during Johnston's term, the Chickasaw Nation had ratified the Atoka Agreement, to allow allotment of communal lands to individual households of tribal members under the Dawes Act.

Johnston lobbied Washington politicians into passing the Supplemental Agreement of 1902 to modify this treaty, in order to allow the Chickasaw and Choctaw to review tribal citizenship cases that had been accepted by the Dawes Commission.

Former Oklahoma Governor William H. Murray in his eulogy of Johnston on June 29, 1939, said:[7] Every allotment, every town lot, every parcel of land sold or transferred from the Nation from west of Duncan and Chickasha to Arkansas, every foot of land south of the Canadian River bears the name of Douglas H. Johnston as grantor, representing sovereignty of that soil.

In August 1906, without consent from the tribal or federal government, an election was held in which Peter Maytubby won the office of Governor.

In 1907, the legislature of the newly created state of Oklahoma tried to nullify a provision of the Atoka Agreement that prohibited taxing for 21 years the lands allotted to Native American heads of household.

[6] In 1924, the Johnston administration won permission to sue the Federal government in the United States Court of Claims and recover money that it had obtained illegally from tribal resources.

[6] The following memorial to Douglas H. Johnston was published in the Chronicles of Oklahoma: (He) stood as the accredited representative of his Nation in all matters affecting the well-being of his people.