He is notable for the Dawes Act (1887), which was intended to stimulate the assimilation of Native Americans by ending the tribal government and control of communal lands.

In 1868, he received 2,000 shares of stock in the Crédit Mobilier of America railroad construction company from Representative Oakes Ames, as part of the Union Pacific railway's influence-buying efforts.

In March 1871, Dawes supported federal financing for Ferdinand Vandeveer Hayden's fifth geological survey of the territories, which became a driving force in the creation of Yellowstone National Park.

In late 1871 and early 1872, Dawes became an ardent supporter of a bill to create Yellowstone National Park in order to preserve its wilderness and resources.

During his long period of legislative activity, Dawes served in the House on the committees on elections, ways and means, and appropriations.

He took a prominent part in passage of the anti-slavery and Reconstruction measures during and after the Civil War, in tariff legislation, and in the establishment of a fish commission.

Well-meaning people such as Dawes believed that the Indians had to assimilate to majority culture to survive, and should take up subsistence farming, still dominant in agriculture.

[4] Along with fellow Massachusetts senatorial Half-Breed George F. Hoar and Rep. John Davis Long, he became one of the faction's leading strategists.

The Maine Republican's credentials as a Half-Breed were spotty due to his history of antipathy towards civil service reform, though nonetheless were welcomed by Hoar and Dawes as a member of the faction.

It was intended to assimilate Indians by breaking up their tribal governments and communal lands, and by encouraging them to undertake subsistence farming, then widespread in American society.

After gaining agreement from representatives of the Five Civilized Tribes in Indian Territory, the commission appointed registrars to register members on rolls prior to allotment of lands.

The Coolidge administration studied the effects of the Dawes Act and the current conditions for Indians in what is known as the Meriam Report, completed in 1928.

[8] Aidan Quinn played Dawes in the film Bury My Heart at Wounded Knee, adapted from a 1970 history of Native Americans, the United States, and the West written by Dee Brown.