Marine Corps Academics Officer Candidates School (OCS) Practice Test

The oath binds a Marine officer to defend the Constitution of the United States. This document is the supreme law that establishes the framework of the government, defines the powers of federal authority, and protects the rights of the people. Defending it means upholding the rule of law and ensuring lawful government actions, even in the face of threats abroad or at home.

The other documents aren’t the pledge you take. The Magna Carta is a medieval English charter that influenced conceptions of rights long ago but isn’t the legal framework you swear to defend today. The Declaration of Independence outlines grievances and the intent to separate from Britain, not a governing charter. The Articles of Confederation was the prior American governing framework but was replaced by the current Constitution; the oath specifically commits to defending the Constitution that is in force now.