---
title: "Big Three Networks — AP Gov Definition & Exam Guide"
description: "The Big Three networks (ABC, CBS, NBC) dominated mid-20th century political news, acting as gatekeepers of national information. Key for AP Gov Topic 5.12 on the media."
canonical: "https://fiveable.me/ap-gov/key-terms/big-three-networks"
type: "key-term"
subject: "AP US Government"
unit: "Unit 5"
---

# Big Three Networks — AP Gov Definition & Exam Guide

## Definition

The Big Three networks (ABC, CBS, and NBC) were the dominant commercial broadcast TV outlets of the mid-20th century whose near-universal nightly news reach made them the main gatekeepers of political information, shaping the agenda, candidate exposure, and public opinion before cable and digital media broke their hold.

## What It Is

The Big Three networks are ABC, CBS, and NBC. For decades in the mid-20th century, these three commercial broadcasters were basically the only game in town for national news. If you wanted to know what happened in Washington, you watched one of three nightly newscasts, and tens of millions of Americans did exactly that every evening.

That near-monopoly gave the Big Three enormous power as gatekeepers. Whatever stories they chose to cover became the national conversation, and whatever they ignored mostly didn't exist for the average voter. Candidates built entire campaign strategies around getting on (or staying off) the evening news. This is the textbook example of agenda setting under the CED's [media](/ap-gov/unit-5 "fv-autolink") essential knowledge. The Big Three era ended gradually as cable channels, then the internet and social media, fragmented the audience and stripped away their gatekeeper role. That before-and-after story is what [AP Gov](/ap-gov "fv-autolink") actually wants you to understand.

## Why It Matters

This term lives in **[Topic 5.12](/ap-gov/unit-5/media/study-guide/n2tB5CMedrPg3ZfvACWu "fv-autolink") (The Media)** in **Unit 5: Political Participation**, and it directly supports learning objective **AP Gov 5.12.A**, which asks you to explain the media's role as a [linkage institution](/ap-gov/key-terms/linkage-institution "fv-autolink"). The Big Three are your historical anchor for that explanation. The CED's essential knowledge says agenda setting happens when traditional news media, new communication technologies, and social media shape how citizens routinely get political information. The Big Three ARE the 'traditional news media' in that sentence. Knowing this era lets you explain change over time, from three gatekeepers everyone watched to thousands of fragmented, often partisan sources you choose yourself. That shift in how citizens acquire information, and what it does to shared facts and political trust, is one of the core arguments Unit 5 wants you to be able to make.

## Connections

### [Gatekeeper (Unit 5)](/ap-gov/key-terms/gatekeeper)

The Big Three networks are the classic real-world example of the media's [gatekeeper](/ap-gov/key-terms/gatekeeper "fv-autolink") role. With only three doors into the national conversation, a handful of network producers effectively decided which issues reached voters at all. When you need a concrete example of gatekeeping on an FRQ, this is it.

### [Linkage Institution (Unit 5)](/ap-gov/key-terms/linkage-institution)

The media is one of the four [linkage institutions](/ap-gov/key-terms/linkage-institutions "fv-autolink") (along with parties, interest groups, and elections) that connect citizens to government. In the Big Three era, that link ran through one narrow pipe. Today the pipe has shattered into thousands of channels, which changes how well the linkage actually works.

### [Fairness Doctrine (Unit 5)](/ap-gov/key-terms/fairness-doctrine)

The [Fairness Doctrine](/ap-gov/key-terms/fairness-doctrine "fv-autolink") made sense in a Big Three world. Because broadcast spectrum was scarce and three networks controlled the news, the FCC required balanced coverage of controversial issues. Once cable multiplied the channels, the scarcity argument collapsed and the doctrine was scrapped in 1987, opening the door to openly partisan outlets.

### [Horse race journalism (Unit 5)](/ap-gov/key-terms/horse-race-journalism)

The CED flags how media use of [polling](/ap-gov/key-terms/polling "fv-autolink") turns elections into 'horse races' focused on who's winning instead of platforms. That style took root in network TV election coverage, where a 30-minute newscast favored simple win-lose narratives over deep policy analysis, and it only intensified after the Big Three lost their monopoly.

## On the AP Exam

This term shows up almost entirely in multiple-choice contexts and as supporting evidence in free-response writing. A typical MCQ asks you to identify which three networks dominated television news (ABC, CBS, NBC) or, more conceptually, to compare the Big Three era to today's fragmented media environment. No released FRQ has used the term verbatim, but it's perfect evidence for an argument or concept-application question on the media as a linkage institution under 5.12.A. The move the exam rewards is change over time. Be ready to explain that the Big Three's near-universal reach meant most Americans shared one set of facts, while cable, the internet, and social media fragmented audiences, increased ideologically driven content, and weakened the media's traditional gatekeeping function.

## Big Three networks vs Cable news networks (CNN, Fox News, MSNBC)

Don't mix these up. The Big Three (ABC, CBS, NBC) are broadcast networks from the era of media scarcity, aiming at a single mass audience with relatively neutral nightly news. Cable news networks came later, run 24 hours a day, and compete for niche audiences, which pushes them toward ideologically distinct coverage. On the exam, the Big Three represent the old consolidated gatekeeper model, while cable news represents the fragmented, narrowcast model that replaced it.

## Key Takeaways

- The Big Three networks are ABC, CBS, and NBC, the commercial broadcasters that dominated American television news through the mid-20th century.
- Their near-universal reach made them powerful gatekeepers, meaning their coverage choices largely set the national policy agenda.
- The Big Three era is your go-to example of traditional news media acting as a linkage institution under learning objective AP Gov 5.12.A.
- Cable television and digital media broke the Big Three's monopoly, fragmenting audiences and weakening the gatekeeper role they once held.
- The shift from three shared news sources to thousands of self-selected ones explains modern problems like partisan media bubbles, a core change-over-time argument in Unit 5.

## FAQs

### What are the Big Three networks in AP Gov?

The Big Three are ABC, CBS, and NBC, the three commercial broadcast networks that dominated national television news and political coverage during the mid-20th century. In AP Gov they appear in Topic 5.12 as the prime example of traditional media gatekeeping.

### Do the Big Three networks still control the news today?

No. ABC, CBS, and NBC still exist and still air nightly newscasts, but cable news, the internet, and social media destroyed their near-monopoly on political information. The AP exam cares about exactly this shift, from three gatekeepers to a fragmented media landscape.

### How are the Big Three networks different from cable news like CNN and Fox?

The Big Three are broadcast networks that served one mass national audience with a short, relatively neutral nightly newscast. Cable networks like CNN (launched 1980) and Fox News run 24/7 and compete for narrower, often ideological audiences. The exam treats them as two different media eras.

### Why do the Big Three networks matter for the AP Gov exam?

They anchor learning objective 5.12.A on the media as a linkage institution. Use them to explain agenda setting, the gatekeeper role, and how new communication technologies changed the way citizens acquire political information.

### What's the connection between the Big Three networks and the Fairness Doctrine?

The Fairness Doctrine required broadcasters to present balanced coverage of controversial issues, a rule justified by the scarcity of channels in the Big Three era. When cable ended that scarcity, the FCC repealed the doctrine in 1987, which helped openly partisan media flourish.

## Related Study Guides

- [5.12 The Media](/ap-gov/unit-5/media/study-guide/n2tB5CMedrPg3ZfvACWu)

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