Coyle v. Smith is a significant Supreme Court case that addressed the authority of Congress in imposing conditions on states after their admission to the Union. The case arose when Oklahoma, which had accepted the stipulation of Guthrie as its capital upon statehood in 1907, sought to relocate its capital to Oklahoma City after three years. Citizens opposed to this move challenged the legality of Congressional conditions, questioning whether such restrictions could remain enforceable post-admission. In a 7-2 ruling, the Supreme Court held that Congress's imposition of conditions that hindered state equality was unconstitutional, thereby affirming Oklahoma's right to designate its own capital. The majority opinion, written by Justice Horace H. Lurton, emphasized that while the Constitution does not explicitly address this scenario, the principle of state equality is a vital, albeit unwritten, tradition. This case highlights the balance of power between federal authority and state sovereignty, illustrating an essential aspect of the relationship between the states and the federal government in the context of American governance.