---
title: "Federalist No. 78 — AP Gov Definition & Exam Guide"
description: "Federalist No. 78 is Hamilton's defense of an independent judiciary and judicial review. A required AP Gov foundational document tied to Topic 2.8 and Marbury."
canonical: "https://fiveable.me/ap-gov/key-terms/federalist-no-78"
type: "key-term"
subject: "AP US Government"
unit: "Unit 2"
---

# Federalist No. 78 — AP Gov Definition & Exam Guide

## Definition

Federalist No. 78 is Alexander Hamilton's essay arguing for an independent judiciary with life tenure and the power of judicial review, calling the courts the "least dangerous" branch because they control neither the sword nor the purse. It's a required foundational document in AP Gov (Topic 2.8).

## What It Is

Federalist No. 78 is [Alexander Hamilton](/ap-gov/key-terms/alexander-hamilton "fv-autolink")'s pitch for why the federal judiciary, as designed in [Article III](/ap-gov/unit-2/judicial-branch/study-guide/y7kYkIyrT8DYX1Ud7Y75 "fv-autolink"), deserves your trust. His core claim is that the courts are the **"least dangerous" branch**. The executive holds the sword (enforcement power) and the legislature holds the purse (spending power), but the judiciary has "neither force nor will, merely judgment." Because the courts are so weak, Hamilton argues, they need protection, not restraint. That's why judges get life tenure during "good behavior" and salaries that can't be cut. Independence lets them rule on the Constitution without fearing political payback.

The essay's biggest move is laying out the logic of **judicial review** decades before *Marbury v. Madison* made it real. Hamilton reasons that the Constitution is the supreme will of the people, ordinary laws are just the will of the legislature, and when the two conflict, courts must side with the Constitution. In [AP Gov](/ap-gov "fv-autolink") terms, Federalist No. 78 is one of the nine required foundational documents, and it pairs directly with Article III as the argument for how an independent judiciary checks the other branches.

## Why It Matters

Federalist No. 78 lives in **Topic 2.8 (The Judicial Branch)** in [Unit 2](/ap-gov/unit-2 "fv-autolink") and directly supports learning objective **2.8.A**: explain the principle of [judicial review](/ap-gov/key-terms/judicial-review "fv-autolink") and how it checks the power of other branches. The CED is explicit that Article III sets up the judiciary's powers while Federalist No. 78 supplies the *argument* for why its independence checks the other branches. That makes this essay the theory behind everything else in the judiciary topics. When you study *Marbury*, life tenure, or debates over an "activist" Court, you're really watching Hamilton's argument play out. It's also one of the most usable foundational documents on the Argument Essay, since prompts about limited government practically beg for it.

## Connections

### [Judicial Review (Unit 2)](/ap-gov/key-terms/judicial-review)

Federalist No. 78 is the blueprint; [Marbury v. Madison](/ap-gov/key-terms/marbury-v-madison "fv-autolink") (1803) is the building. Hamilton wrote the justification for courts striking down unconstitutional laws, and Chief Justice Marshall borrowed that exact logic to claim the power for the Supreme Court.

### [Separation of Powers (Unit 1)](/ap-gov/key-terms/separation-of-powers)

Hamilton's "sword, purse, judgment" framing only makes sense inside Madison's separation-of-powers design from [Federalist No. 51](/ap-gov/key-terms/federalist-no-51 "fv-autolink"). Each branch gets a different kind of power, and the judiciary's weakness in force and money is exactly why it needs structural independence.

### [Checks and Balances (Unit 1)](/ap-gov/key-terms/checks-and-balances)

Judicial review is the [judiciary](/ap-gov/key-terms/judiciary "fv-autolink")'s signature check on Congress and the president. Federalist No. 78 explains why an unelected branch should hold that check: courts answer to the Constitution (the people's permanent will), not to whichever majority controls the legislature this term.

### [Brown v. Board of Education (Unit 3)](/ap-gov/key-terms/brown-v-board-of-education)

Brown shows Hamilton's argument working in practice. An independent, life-tenured Court struck down segregation laws that elected legislatures had passed and voters supported, exactly the kind of constitutional guardianship Federalist No. 78 promised.

## On the AP Exam

On the multiple-choice section, Federalist No. 78 shows up as an excerpt you have to interpret. Common stems ask which constitutional principle supports the judiciary checking other branches (judicial review), why the judiciary needs independence (life tenure protects judges from political pressure), and how its power compares to the other branches (weakest, since it lacks the sword and the purse). On the FRQ side, this document is a go-to for the Argument Essay. College Board has used the prompt asking whether an elected legislature or an independent judiciary better preserves limited government (it appeared in 2015 and again as the 2025 Argument Essay Q4), and Federalist No. 78 is the obvious foundational document for the judiciary side. To score, you can't just name-drop it. You have to use Hamilton's actual reasoning, like life tenure insulating judges from majorities or courts defending the Constitution against unconstitutional laws, as evidence for your thesis.

## Federalist No. 78 vs Marbury v. Madison

Federalist No. 78 is an argument; Marbury v. Madison is an action. Hamilton's 1788 essay made the theoretical case that courts *should* be able to strike down unconstitutional laws. The 1803 Marbury decision is where the Supreme Court actually claimed that power and used it. If a question asks where judicial review was *argued for*, the answer is Federalist No. 78. If it asks where judicial review was *established*, the answer is Marbury.

## Key Takeaways

- Federalist No. 78 is Alexander Hamilton's essay defending an independent judiciary and laying out the logic of judicial review before Marbury v. Madison established it.
- Hamilton calls the judiciary the "least dangerous" branch because it controls neither the sword (enforcement) nor the purse (money), only judgment.
- Life tenure during good behavior is the essay's solution to judicial weakness, since judges who can't be fired for unpopular rulings can defend the Constitution against political majorities.
- Hamilton's judicial review logic is simple: the Constitution is the people's supreme will, so when a regular law conflicts with it, courts must side with the Constitution.
- In the CED, Article III provides the judiciary's powers while Federalist No. 78 provides the argument for its independence, both grounding learning objective 2.8.A.
- It's one of the nine required foundational documents, and it's prime evidence on Argument Essay prompts about limited government and an independent judiciary.

## FAQs

### What is Federalist No. 78 and what does it argue?

Federalist No. 78 is a 1788 essay by Alexander Hamilton defending the Article III judiciary. It argues that courts need independence (through life tenure) and the power of judicial review so they can strike down laws that violate the Constitution.

### Did Federalist No. 78 establish judicial review?

No. Federalist No. 78 argued that courts should have judicial review, but the Supreme Court didn't actually establish the power until Marbury v. Madison in 1803. The exam loves this distinction: Hamilton made the case, Marshall made it law.

### Why does Hamilton call the judiciary the "least dangerous" branch?

Because it has "neither force nor will, merely judgment." The executive controls enforcement (the sword) and Congress controls spending (the purse), so courts can't compel anyone on their own. That weakness is Hamilton's argument for why judicial independence is safe, not threatening.

### How is Federalist No. 78 different from Federalist No. 51?

Federalist No. 51 (Madison) explains the overall system of separation of powers and checks and balances across all branches. Federalist No. 78 (Hamilton) zooms in on one branch, the judiciary, arguing for its independence and its power of judicial review.

### Is Federalist No. 78 a required document for the AP Gov exam?

Yes. It's one of the nine required foundational documents, tied to Topic 2.8 and learning objective 2.8.A. Expect MCQ excerpts from it, and expect it as strong evidence on Argument Essay prompts about an independent judiciary and limited government.

## Related Study Guides

- [2.8 The Judicial Branch](/ap-gov/unit-2/judicial-branch/study-guide/y7kYkIyrT8DYX1Ud7Y75)

## Structured Data

```json
{"@context":"https://schema.org","@graph":[{"@type":"LearningResource","@id":"https://fiveable.me/ap-gov/key-terms/federalist-no-78#resource","name":"Federalist No. 78 — AP Gov Definition & Exam Guide","url":"https://fiveable.me/ap-gov/key-terms/federalist-no-78","learningResourceType":"Concept explainer","educationalLevel":"AP / High School","about":{"@id":"https://fiveable.me/ap-gov/key-terms/federalist-no-78#term"},"audience":{"@type":"EducationalAudience","educationalRole":"student"},"dateModified":"2026-06-11T00:48:31.347Z","isPartOf":{"@type":"Collection","name":"AP US Government Key Terms","url":"https://fiveable.me/ap-gov/key-terms"},"publisher":{"@type":"Organization","name":"Fiveable","url":"https://fiveable.me"}},{"@type":"DefinedTerm","@id":"https://fiveable.me/ap-gov/key-terms/federalist-no-78#term","name":"Federalist No. 78","description":"Federalist No. 78 is Alexander Hamilton's essay arguing for an independent judiciary with life tenure and the power of judicial review, calling the courts the \"least dangerous\" branch because they control neither the sword nor the purse. It's a required foundational document in AP Gov (Topic 2.8).","url":"https://fiveable.me/ap-gov/key-terms/federalist-no-78","inDefinedTermSet":{"@type":"DefinedTermSet","name":"AP US Government Key Terms","url":"https://fiveable.me/ap-gov/key-terms"},"educationalAlignment":[{"@type":"AlignmentObject","alignmentType":"educationalSubject","educationalFramework":"AP Course and Exam Description","targetName":"AP Gov Unit 2, Topic 2.8, LO 2.8.A"}]},{"@type":"FAQPage","mainEntity":[{"@type":"Question","name":"What is Federalist No. 78 and what does it argue?","acceptedAnswer":{"@type":"Answer","text":"Federalist No. 78 is a 1788 essay by Alexander Hamilton defending the Article III judiciary. It argues that courts need independence (through life tenure) and the power of judicial review so they can strike down laws that violate the Constitution."}},{"@type":"Question","name":"Did Federalist No. 78 establish judicial review?","acceptedAnswer":{"@type":"Answer","text":"No. Federalist No. 78 argued that courts should have judicial review, but the Supreme Court didn't actually establish the power until Marbury v. Madison in 1803. The exam loves this distinction: Hamilton made the case, Marshall made it law."}},{"@type":"Question","name":"Why does Hamilton call the judiciary the \"least dangerous\" branch?","acceptedAnswer":{"@type":"Answer","text":"Because it has \"neither force nor will, merely judgment.\" The executive controls enforcement (the sword) and Congress controls spending (the purse), so courts can't compel anyone on their own. That weakness is Hamilton's argument for why judicial independence is safe, not threatening."}},{"@type":"Question","name":"How is Federalist No. 78 different from Federalist No. 51?","acceptedAnswer":{"@type":"Answer","text":"Federalist No. 51 (Madison) explains the overall system of separation of powers and checks and balances across all branches. Federalist No. 78 (Hamilton) zooms in on one branch, the judiciary, arguing for its independence and its power of judicial review."}},{"@type":"Question","name":"Is Federalist No. 78 a required document for the AP Gov exam?","acceptedAnswer":{"@type":"Answer","text":"Yes. It's one of the nine required foundational documents, tied to Topic 2.8 and learning objective 2.8.A. Expect MCQ excerpts from it, and expect it as strong evidence on Argument Essay prompts about an independent judiciary and limited government."}}]},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"AP US Government","item":"https://fiveable.me/ap-gov"},{"@type":"ListItem","position":2,"name":"Key Terms","item":"https://fiveable.me/ap-gov/key-terms"},{"@type":"ListItem","position":3,"name":"Unit 2","item":"https://fiveable.me/ap-gov/unit-2"},{"@type":"ListItem","position":4,"name":"Federalist No. 78"}]}]}
```