Coyle v. Smith, 221 U.S. 559 (1911), was a Supreme Court of the United States case that held that the newly created state of Oklahoma was permitted to move its capital city from Guthrie to Oklahoma City, notwithstanding the Enabling Act provision that prohibited it from being moved from Guthrie until after 1913.

Section 497 of the Oklahoma Constitution stated that the terms of the U.S. Congress's enabling act of 1906—which allowed Oklahoma to create a state constitution and be admitted to the Union—were "accepted by ordinance irrevocable".

Coyle, owner of large property interests in Guthrie, sued the state of Oklahoma, arguing that the move was performed in violation of the state constitution's acceptance of the terms of Congress's enabling act.

If she has, she, by virtue of her jurisdictional sovereignty as such a state, may determine for her own people the proper location of the local seat of government.

[1] Quoting Chief Justice Chase's opinions regarding the indestructibility of the Union and the principle of federalism contained in Texas v. White and Lane County v. Oregon, the opinion concludes: To this we may add that the constitutional equality of the States is essential to the harmonious operation of the scheme upon which the Republic was organized.