---
title: "Katzenbach v. McClung — AP Gov Definition & Exam Guide"
description: "Katzenbach v. McClung (1964) upheld the Civil Rights Act under Congress's commerce power. See how it links Unit 2 congressional power to federalism and Lopez."
canonical: "https://fiveable.me/ap-gov/key-terms/katzenbach-v-mcclung"
type: "key-term"
subject: "AP US Government"
unit: "Unit 2"
---

# Katzenbach v. McClung — AP Gov Definition & Exam Guide

## Definition

Katzenbach v. McClung (1964) is the Supreme Court case that upheld the Civil Rights Act of 1964, ruling Congress could use its Commerce Clause power to ban racial discrimination in restaurants because that discrimination significantly burdened interstate commerce.

## What It Is

Katzenbach v. McClung (1964) asked a simple-sounding question with huge stakes. Could [Congress](/ap-gov/unit-1/principles-american-government/study-guide/BXlQvFOiaKwhntWYhgKP "fv-autolink") force Ollie's Barbecue, a family-owned restaurant in Birmingham, Alabama, to serve Black customers? The restaurant argued it was a purely local business, so Congress had no authority over it. The [Supreme Court](/ap-gov/key-terms/supreme-court "fv-autolink") disagreed unanimously. Because the restaurant bought a large share of its food through interstate commerce, and because discrimination discouraged Black Americans from traveling and spending money, Congress could regulate it under the Commerce Clause.

The ruling matters for [AP Gov](/ap-gov "fv-autolink") because it shows how broadly the Court was willing to read Congress's enumerated power to regulate interstate commerce. Title II of the Civil Rights Act of 1964 banned discrimination in public accommodations, and McClung gave that ban constitutional teeth. Think of it this way: the case turned the Commerce Clause into the legal engine that powered civil rights legislation. Congress couldn't directly outlaw private racism, but it could regulate the economic activity that racism touched, which turned out to be almost everything.

## Why It Matters

This case lives in Topic 2.2 (Structures, Powers, and Functions of Congress) in [Unit 2](/ap-gov/unit-2 "fv-autolink"), supporting learning objective AP Gov 2.2.A, which asks you to explain how Congress's powers affect [policymaking](/ap-gov/key-terms/policymaking "fv-autolink"). McClung is the proof-of-concept that Congress's enumerated commerce power, stretched by judicial interpretation, lets it legislate on issues that look local and social rather than national and economic. It also threads directly into Unit 1's federalism debate, because every Commerce Clause case is really a fight over the line between federal and state authority. When you study how Congress makes policy, McClung is the example of the Court saying yes to expansive congressional power, the bookend to United States v. Lopez (1995) saying no.

## Connections

### [Civil Rights Act of 1964 (Unit 2)](/ap-gov/key-terms/civil-rights-act-of-1964)

McClung is the case that made the Civil Rights Act stick. Congress passed the law, but it only survived because the Court accepted the [Commerce Clause](/ap-gov/key-terms/commerce-clause "fv-autolink") as its constitutional foundation. Law and case work as a pair: one is the policy, the other is the green light.

### [United States v. Lopez (Unit 1)](/ap-gov/key-terms/united-states-v-lopez)

Lopez (1995) is the required SCOTUS case where the Court finally said the Commerce Clause has limits, striking down the [Gun-Free School Zones Act](/ap-gov/key-terms/gun-free-school-zones-act "fv-autolink"). McClung and Lopez are the two ends of the spectrum. Pair them whenever a question asks how interpretations of congressional power have changed over time.

### Federalism and the Commerce Clause (Unit 1)

Every expansion of the commerce power shifts the federal-state balance toward Washington. McClung shows fiscal-era [federalism](/ap-gov/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO "fv-autolink") logic in action, where a local restaurant becomes a federal matter because its supply chain crosses state lines.

### [Committee Hearings (Unit 2)](/ap-gov/key-terms/committee-hearings)

Before the Civil Rights Act ever reached the Court, Congress built a record through committee hearings documenting how discrimination burdened interstate commerce. That legislative fact-finding is exactly what the Court leaned on in McClung, a nice example of the Topic 2.2 lawmaking process feeding judicial review.

## On the AP Exam

Katzenbach v. McClung appeared as the stimulus for a 2024 SAQ (Question 3), which means the College Board expects you to read a non-required case and connect it to a required one. That's the classic SCOTUS comparison SAQ format. The move you have to make is linking McClung's broad reading of the Commerce Clause to United States v. Lopez's narrow one, then explaining what that tells you about congressional power or federalism. In multiple choice, expect stems about which constitutional provision justified the Civil Rights Act (answer: the Commerce Clause, not the 14th Amendment's Equal Protection Clause, since that clause restricts state action, not private businesses). You don't need to memorize case details, but you do need to recognize the commerce-power reasoning when a stimulus hands it to you.

## Katzenbach v. McClung vs Heart of Atlanta Motel v. United States

These are companion cases decided the same day in 1964, and both upheld the Civil Rights Act under the Commerce Clause. The difference is the business. Heart of Atlanta involved a motel serving interstate travelers, an easy commerce connection. McClung involved a local restaurant, so the Court had to reach further, relying on the food it bought from out of state and the cumulative effect of discrimination on the economy. McClung is the bolder ruling because it showed the commerce power reaches even mostly local businesses.

## Key Takeaways

- Katzenbach v. McClung (1964) unanimously upheld the Civil Rights Act of 1964 as a valid use of Congress's Commerce Clause power.
- The Court ruled that even a local restaurant like Ollie's Barbecue fell under federal regulation because its food supply and the cumulative effect of discrimination burdened interstate commerce.
- The case shows how a broad judicial interpretation of an enumerated power lets Congress make policy on issues that look local or social, which is the core of learning objective AP Gov 2.2.A.
- McClung pairs with United States v. Lopez (1995) as the expansion-versus-limit bookends of Commerce Clause interpretation, a favorite SCOTUS comparison setup.
- Congress used the Commerce Clause, not the 14th Amendment, to ban private discrimination, because the Equal Protection Clause only restricts government action.

## FAQs

### What is Katzenbach v. McClung in AP Gov?

It's the 1964 Supreme Court case upholding the Civil Rights Act of 1964, ruling that Congress could ban racial discrimination at a local restaurant (Ollie's Barbecue in Birmingham) under its Commerce Clause power. It shows up in Topic 2.2 as an example of broad congressional power.

### Is Katzenbach v. McClung a required Supreme Court case for AP Gov?

No, it's not one of the 15 required cases. But it appeared as a stimulus on the 2024 SAQ, where you had to compare it to a required case like United States v. Lopez. You need to be able to reason through it, not memorize it.

### How is Katzenbach v. McClung different from Heart of Atlanta Motel?

Both were decided the same day in 1964 and both upheld the Civil Rights Act, but Heart of Atlanta involved a motel serving interstate travelers while McClung involved a local restaurant. McClung went further by holding that the cumulative economic effects of discrimination, plus out-of-state food purchases, were enough of a commerce connection.

### Did Katzenbach v. McClung use the 14th Amendment?

No, and that's the trap answer on multiple choice. The Equal Protection Clause restricts state governments, not private businesses, so Congress justified the Civil Rights Act under its Article I power to regulate interstate commerce, and the Court upheld it on those grounds.

### How does Katzenbach v. McClung connect to United States v. Lopez?

They're opposite outcomes on the same question of how far the Commerce Clause stretches. McClung (1964) approved a very broad reading, while Lopez (1995) marked the first modern limit, striking down a federal gun-free school zones law as too disconnected from commerce. Comparing them is a classic SAQ move.

## Related Study Guides

- [2.2 Structures, Powers, and Functions of Congress](/ap-gov/unit-2/structures-powers-functions-congress/study-guide/zHM0wXD3wtKBOJe1wrvE)

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