美利坚合众国宪法第四条

宪法正文I ∙ II ∙ III ∙ IV ∙ V ∙ VI ∙ VII其它修正案 XI ∙ XII ∙ XIII ∙ XIV ∙ XV XVI ∙ XVII ∙ XVIII ∙ XIX ∙ XX XXI ∙ XXII ∙ XXIII ∙ XXIV ∙ XXV XXVI ∙ XXVII美利坚合众国宪法第四条规定了美国各州的责任、新州的加入，以及联邦和各州的相应权限。其中还包括有劳役逃犯条款（英语：Fugitive Slave Clause），这一条款的主要目的是为了防止蓄奴州的黑奴在逃往自由州后就自动成为了自由公民。而旨在废除奴隶制的美利坚合众国宪法第十三条修正案于1865年12月6日通过后，这一条款就已经没有了意义。Full Faith and Credit shall be given in each State to the public Acts, Records, and judicial Proceedings of every other State. And the Congress may by general Laws prescribe the Manner in which such Acts, Records and Proceedings shall be proved, and the Effect thereof.第一款要求各州“对于他州的公共法律、案卷和司法程序”“给予充分信任和尊重”，并且国会可以通过法律来保证其效力。联邦最高法院在1813年对“米尔斯诉杜里案”（"Mills v. Duryee"，1t1 U.S. (7 Cranch) 481 (1813)）的判决中裁定，任何一州内法庭的判决结果，其他各州法院也必须给予认可；联邦法院也不能够重审任何州法院中已经裁决的案件。之后，首席大法官约翰·马歇尔进一步补充建议各州法院的司法判决必须被其他州法院视为最终判决而接受。不过在1839年的麦克艾尔摩尔诉科恩案（英语：McElmoyle v. Cohen）（38 U.S. (13 Pet.) 312 (1839)）中，南卡罗莱纳州的一个判决由于其申请进入乔治亚州执行的时限已过，因此被拒绝执行。联邦最高法院在这个案子上支持了乔治亚州的意见，指出根据程序法，南卡罗莱纳州应该在法院依法规定的时限内进入乔治亚州执法。The Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States.A Person charged in any State with Treason, Felony, or other Crime, who shall flee from Justice, and be found in another State, shall on demand of the executive Authority of the State from which he fled, be delivered up, to be removed to the State having Jurisdiction of the Crime.No Person held to Service or Labour in one State, under the Laws thereof, escaping into another, shall, in Consequence of any Law or Regulation therein, be discharged from such Service or Labour, but shall be delivered up on Claim of the Party to whom such Service or Labour may be due.New States may be admitted by the Congress into this Union; but no new States shall be formed or erected within the Jurisdiction of any other State; nor any State be formed by the Junction of two or more States, or parts of States, without the Consent of the Legislatures of the States concerned as well as of the Congress.根据第三款，国会可以接受新的州加入联邦。The Congress shall have power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States; and nothing in this Constitution shall be so construed as to Prejudice any Claims of the United States, or of any particular State.The United States shall guarantee to every State in this Union a Republican Form of Government,and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.这一节要求合众国保护各州免受入侵，并应各州议会或州行政长官（在州议会不能召开时）的请求平定内乱，这一规定曾于1967年底特律骚乱期间被讨论，但最终并没有使用。