The Treaty of Paris 1898 and the Cession of Puerto Rico to the United States

The Treaty of Paris, signed on December 10, 1898, formally ended the Spanish-American War and transferred sovereignty over Puerto Rico from Spain to the United States. This transfer established the foundational legal relationship between Puerto Rico and the federal government — a relationship that has shaped every dimension of the island's political status, citizenship rights, and constitutional standing for over 125 years. The treaty's terms and the legal framework erected in its aftermath remain the subject of active legislative debate, federal court litigation, and ongoing status referendums.

Definition and scope

The Treaty of Paris 1898 is a bilateral international agreement concluded between the United States and Spain following the conclusion of hostilities initiated in April 1898. Article II of the treaty required Spain to cede Puerto Rico and other islands in the West Indies to the United States in perpetuity. The cession was unconditional — no purchase price was paid for Puerto Rico specifically, distinguishing it from the Philippines, for which the United States paid Spain $20 million (Treaty of Paris, 1898, Article III, Yale Avalon Project).

The treaty did not define the citizenship status of Puerto Rican inhabitants. Article IX stated only that civil rights and political status of the native inhabitants of the territories ceded would be "determined by Congress." This deliberate ambiguity delegated to the legislative branch the authority to establish Puerto Rico's legal position within the U.S. constitutional framework — a delegation with consequences that persist through the Insular Cases Supreme Court doctrine and the Territorial Clause of the U.S. Constitution.

The scope of the cession encompassed Puerto Rico as an unincorporated territory — a legal category that Congress and the federal courts subsequently developed through a series of Supreme Court decisions beginning in 1901. The distinction between incorporated and unincorporated territories is examined in depth at Incorporated vs. Unincorporated Territories Explained.

How it works

The treaty's operative mechanism functioned in three stages:

1. Military transfer: Following the cessation of hostilities in August 1898, U.S. military forces assumed control of Puerto Rico. Spanish administrative authority terminated upon the treaty's ratification by the U.S. Senate on February 6, 1899.
2. Legislative governance: Congress assumed plenary authority over Puerto Rico under Article IV, Section 3 of the U.S. Constitution (the Territorial Clause), which grants Congress power to make rules and regulations for U.S. territories. No constitutional provisions applied automatically to Puerto Rico as a result of the cession alone.
3. Statutory civil framework: Congress enacted the Foraker Act of 1900, which established the first civilian government for Puerto Rico and created a resident commissioner position in Washington — a non-voting representative role described at Puerto Rico Resident Commissioner Role.

Citizenship was not extended at the moment of cession. Puerto Ricans were classified as "citizens of Puerto Rico" and "nationals of the United States" — a hybrid status lacking full constitutional protections. Collective U.S. citizenship was granted only through the Jones Act of 1917, nearly two decades after the treaty took effect.

Treaty of Paris 1898 vs. Louisiana Purchase 1803 — Territorial Disposition Comparison

Common scenarios

Several recurring legal and policy scenarios derive directly from the 1898 cession framework:

• Federal benefits eligibility disputes: Because Puerto Rico entered as an unincorporated territory, federal statutory programs — including Medicaid funding formulas — have been applied differently than in the 50 states. The Puerto Rico Federal Funding Disparities page documents the structural inequities traceable to this original territorial designation.
• Voting rights limitations: U.S. citizens residing in Puerto Rico cannot vote in presidential elections and have no voting representation in Congress — a condition that flows directly from Puerto Rico's unincorporated status established at cession. The full scope of this limitation is analyzed at Puerto Rico Voting Rights in Federal Elections.
• Status referendum cycles: Since 1967, Puerto Rico has held 6 status referendums addressing statehood, independence, and continued territorial status — all referendums whose legal framing traces back to the unresolved political status created by Article IX of the 1898 treaty. Results are documented at Puerto Rico Status Referendums Results.
• Constitutional rights litigation: Courts have repeatedly addressed which constitutional protections apply to Puerto Rico's residents, with outcomes shaped by the Insular Cases doctrine erected in the treaty's immediate aftermath. The Puerto Rico Constitutional Rights Limitations page catalogs the operative distinctions.

For comprehensive reference on Puerto Rico's government structure as it developed from the post-treaty legislative framework, Puerto Rico Government Authority provides structured documentation of the island's executive, legislative, and judicial institutions — including the roles established by statutes that Congress enacted under the plenary authority conferred by the 1898 cession.

Decision boundaries

The treaty itself establishes firm legal boundaries that continue to govern subsequent analysis:

What the treaty determined permanently:
- Spain's relinquishment of sovereignty over Puerto Rico is absolute and irrevocable under international law.
- The United States holds full sovereignty over Puerto Rico unless Congress enacts legislation altering that relationship.
- No territory-level government action can supersede the plenary authority Congress holds under Article IX's delegation mechanism.

What the treaty left unresolved — and who resolves it:
- The political status of Puerto Rico (statehood, independence, free association, or continued territorial status) is a matter for Congress and, in some frameworks, mutual agreement with Puerto Rico's population. No administrative or judicial body can unilaterally resolve status. Legislative proposals are tracked at Puerto Rico Democracy Act Status Legislation.
- The extent to which the U.S. Constitution applies to Puerto Rico is determined by federal courts applying the Insular Cases doctrine, not by the treaty text itself.
- Economic and fiscal arrangements — including the debt restructuring supervised by the PROMESA Oversight Board established by Congress in 2016 — operate under statutory authority that Congress can modify. That structure is documented at PROMESA Oversight Board Puerto Rico.

The Puerto Rico Territory Authority main index situates the 1898 treaty within the broader arc of Puerto Rico's political and legal history, from the Foraker Act through the 21st-century status debates.

References

• Treaty of Paris, December 10, 1898 — Yale Avalon Law Project
• Foraker Act (Organic Act of 1900) — Library of Congress
• Jones-Shafroth Act, 1917 (39 Stat. 951) — U.S. Senate Historical Office
• Territorial Clause, Article IV §3 — National Archives, U.S. Constitution
• Insular Cases — Cornell Legal Information Institute
• PROMESA, Pub. L. 114-187 (2016) — U.S. Congress
• Puerto Rico Status Referendums — Puerto Rico State Elections Commission (CEE)