Meta description: Discover what is often called the first U.S. law, why the answer depends on the definition, and how early colonial and federal laws shaped American government.
The answer depends on what “America” means. English colonies had laws long before the United States existed, and the national government operated under more than one system before the Constitution took effect. For the federal government created by the Constitution, the first act passed by Congress and signed into law was the Oaths Act of 1789. But it was not the first law made on American soil. Understanding that distinction reveals how lawmaking developed from colonial assemblies to the modern United States.
The Short Answer: The Oaths Act of 1789
The first law enacted by the new U.S. Congress under the Constitution was formally titled An Act to regulate the Time and Manner of administering certain Oaths. It became law on June 1, 1789, when President George Washington signed it. The statute established how members of Congress and federal officials would take the oath required by the Constitution.
The law addressed a practical first step: before federal officials could carry out their duties, they needed to make the constitutional oath. Article VI of the Constitution requires federal and state officials to support the Constitution by oath or affirmation, while prohibiting religious tests for federal office. Congress’s first statute supplied a procedure for administering the oath to its members and other covered officials.
The statute is often called the first federal law under the Constitution, or the first act of the First Congress. That description is more precise than saying it was the first law in America. It refers to the first act passed by Congress and signed by the president after the new constitutional government began operating.
Why the First Law Was About Oaths
The First Congress met in New York City in March 1789, but it did not immediately begin passing ordinary legislation. Establishing the new government required procedural decisions, including setting a quorum and organizing each chamber. Congress also had to address the constitutional oath so that representatives and senators could formally take office and begin legislative work.
The Oaths Act provided a specific formula and process. Its first section required members of Congress to take an oath or affirmation to support the Constitution. It also directed that the oath be administered in each chamber, with the Senate’s president or a designated senator administering it to senators and the Speaker of the House administering it to representatives.
The statute included federal officials beyond members of Congress. It covered officers appointed under the authority of the United States, as well as certain officials in the states responsible for administering federal law. This helped put the Constitution’s oath requirement into practice across the new national system.
The law was short, but its role was foundational. It helped establish that the new government’s authority rested on the Constitution and that public officials were accountable to that governing document. The oath was not a religious test; the Constitution explicitly barred such tests for federal office.
Was the First Law the Tariff Act of 1789?
Some accounts identify the Tariff Act of 1789 as the first federal law. The confusion arises because the Oaths Act and the tariff legislation were both among Congress’s earliest acts, and the tariff law is often described as the first major piece of legislation or the first law establishing a federal revenue system.
The tariff measure, officially titled An Act for laying a Duty on Goods, Wares and Merchandise imported into the United States, was signed by Washington on July 4, 1789. It imposed duties on imported goods, with the stated goals of raising revenue, paying national debts, and encouraging domestic manufacturing. It became a landmark in the development of federal economic policy.
In a question about the first act passed and signed by the first Congress, the Oaths Act is the direct answer. In a question about the first significant revenue law, the tariff act is often the answer. The two descriptions refer to different measures of “first,” rather than necessarily contradicting one another.
What Counts as “America”?
The phrase “first law enacted in America” can mean several things: the first rule or agreement on the continent, the first law in an English colony, the first law passed by a colonial assembly, or the first statute of the United States. Those are different historical questions. There was no single national legislature governing the entire continent before the United States formed.
Before European colonization, Indigenous nations across North America had their own legal traditions, political institutions, and systems for resolving disputes. These systems varied widely and were not a single body of law. A history of American law that begins only with English colonial statutes leaves out those longstanding Indigenous legal orders.
European colonies also had separate governments and legal systems. Spanish, French, Dutch, and English authorities governed different territories at different times. Even within English America, laws varied by colony. As a result, historians cannot identify one statute as the first law ever made or applied across all of what is now the United States.
Early Laws in the English Colonies
One early English colonial lawmaking body was the Virginia General Assembly, which met at Jamestown in 1619. It adopted measures concerning the colony’s government, economy, and social order. These actions are often cited among the earliest laws enacted by an elected representative assembly in English America, but they were not the first laws on the continent.
Another frequently mentioned document is the Mayflower Compact, signed by English settlers in 1620 before they landed at Plymouth. The compact was an agreement among its signers to form a “civil body politic” and make laws for the community. It is important in the history of self-government, but it is not generally treated as the first statute enacted in America. It was a governing agreement, not an act passed by a legislature in the modern sense.
These examples matter because they show different forms of early lawmaking: colonial assemblies passed measures, while settlers also used agreements to organize communities. Neither one was a national law for the future United States.
What About the First Laws of the United States Under the Articles of Confederation?
The United States existed as an independent nation before the Constitution took effect. From 1781 to 1789, the country’s central government operated under the Articles of Confederation. The Articles created a Congress but gave it limited powers, including no general authority to tax individuals directly.
During this period, the Confederation Congress passed important measures governing western lands. The Land Ordinance of 1785 established a system for surveying and dividing much of the territory northwest of the Ohio River into townships and sections. It influenced the orderly sale and settlement of public lands and reserved land in each township for public education.
The Northwest Ordinance of 1787 created a framework for governing the Northwest Territory and for admitting new states on an equal footing with the original states. It also prohibited slavery in the territory, although it included a fugitive-slave provision. These ordinances were national legislation under the Confederation, not laws passed under the later constitutional government.
Thus, “first U.S. law” can refer either to laws passed by the Confederation Congress or to laws passed by Congress under the Constitution. The Oaths Act is the latter. The earlier ordinances show that national lawmaking did not begin from nothing in 1789.
How Historians Distinguish These “Firsts”
Historical claims about a “first law” usually depend on the institution, territory, and type of legal document being discussed. A useful way to evaluate the claim is to ask three questions: Which government made the law? What territory did it govern? Was the document a statute, an ordinance, a charter, or an agreement?
| Meaning of “first” | Commonly cited example | Why the distinction matters |
|---|---|---|
| First act of Congress under the Constitution | Oaths Act, June 1, 1789 | It was the first statute passed by the first Congress and signed by the president. |
| First major federal revenue law | Tariff Act, July 4, 1789 | It established duties on imports to raise revenue and support national economic policy. |
| Early national law under the Articles | Land Ordinance of 1785 or Northwest Ordinance of 1787 | These were important Confederation-era measures, adopted before the Constitution took effect. |
| Early colonial representative legislation | Measures of the Virginia General Assembly, 1619 | They were colonial laws, not laws of the United States. |
| Early self-governing agreement | Mayflower Compact, 1620 | It was a community agreement rather than a federal statute. |
How the First Congress Built the Federal Government
The Oaths Act was only one piece of a larger effort to make the Constitution workable. The First Congress also established federal departments, organized the federal court system, addressed national finances, and proposed amendments. Its work helped translate the Constitution’s broad framework into functioning institutions.
The Judiciary Act of 1789, for example, created the structure of the federal court system, including district courts and circuit courts, and established the office of attorney general. The act was signed later in 1789. Congress also passed legislation addressing federal revenue, customs administration, and the executive departments.
This sequence illustrates why calling one act “the first law” can obscure the broader story. The first statute established an oath procedure; other early laws built the courts, revenue system, and administrative capacity required for national governance.
Where to Verify the Historical Record
Readers can consult primary sources rather than relying only on simplified summaries. The U.S. Statutes at Large reproduces the Oaths Act in volume one. The U.S. Senate Historical Office describes the opening work of the First Congress, and the National Archives provides access to founding-era documents.
For colonial and Confederation-era context, the Library of Congress and the National Archives provide collections on early American government and law. When checking a claim, the act’s official title, date, and government of origin are especially useful details: they clarify whether the source is discussing the first federal statute under the Constitution, a colonial measure, or an earlier national ordinance.
The Most Accurate Answer
If “America” means the United States under the Constitution, the first law enacted was the Oaths Act of 1789, signed by George Washington on June 1. If the question means the first important federal revenue law, the answer is the Tariff Act of July 4, 1789. If it refers to American law more broadly, there is no single first law: Indigenous legal systems, colonial governments, and the Confederation Congress all preceded the constitutional government.