The 1860 United States Census[1] shows the family living in Creek Nation, Indian Lands, Arkansas.

She was next appointed by President Theodore Roosevelt as the United States postmaster of Muskogee, Oklahoma, serving from 1905 to 1913.

[2] During World War I, she provided a canteen service to local troops in what was the start of the Muskogee Chapter of the American Red Cross.

She was elected by the 2nd District of Oklahoma as a Republican Representative to the 67th Congress, narrowly defeating the incumbent William Hastings.

Before the expiration of her term, Rebecca Felton was appointed for one day to the Senate, and representatives Winnifred Huck from Illinois and Mae Nolan from California both won special elections; they were the third, fourth, and fifth women to serve in Congress.

[3] Robertson was the first woman elected to Congress after passage of the 19th Amendment to the Constitution guaranteeing women the right to vote.

Robertson voted against bills funding maternity and childcare on the grounds that they were an unwarranted governmental intrusion on personal rights.

Robertson was appointed by President Warren G. Harding as a welfare worker at Veterans Hospital Number 90 at Muskogee in May 1923.