Collector v. Day is a 1871 Supreme Court case that held a state could not tax income from a federal salary. In Constitutional Law I, it is a classic intergovernmental immunities case.
Collector v. Day is an early Supreme Court decision in Constitutional Law I about intergovernmental immunities, which is the idea that one level of government cannot use taxes or regulation to interfere with the basic work of the other. The case said a state could not tax the salary of a federal official, because that would let the state reach into federal operations.
The dispute came from a state tax collector trying to tax the income of a federal marshal. That sounds small, but the Court treated it as a structural problem. If states could tax federal officers whenever they wanted, they could make federal service more expensive, less attractive, or even harder to carry out.
Justice William Strong wrote the opinion for the Court and framed the issue as one of constitutional balance. The federal government and the states are separate sovereigns, and each needs room to function without the other reaching too far into its core operations. The Court’s reasoning was not that federal employees should never pay any tax in any form, but that a state could not single out federal pay in a way that burdened federal authority.
This case became a classic statement of federal immunity from state interference. It fit an older, broader view of federalism, where the Court often treated the two governments as occupying separate spheres. Later doctrine narrowed that approach and moved toward more allowance for overlapping taxation, so Collector v. Day is also useful as a snapshot of how constitutional thinking about federalism has changed over time.
For class discussion, the case usually shows up as an example of how the Court protects national functions from state control. It is less about the dollar amount and more about the constitutional principle behind the tax. If a state tax targets a federal operation itself, that raises a red flag under intergovernmental immunity.
Collector v. Day matters because it gives you an early, concrete example of how Constitutional Law I treats the relationship between state power and federal power. The case shows that federalism is not just a map of who does what, it also limits how far one sovereign can reach into the other’s operations.
It is especially useful for understanding the intergovernmental immunities doctrine. When you see a problem about a state tax, a state regulation, or a federal officer’s work, this case gives you the basic instinct to ask whether the burden is aimed at a federal function. That is the kind of move professors expect in a case analysis or short essay.
The case also helps you track doctrine over time. Early cases like this used a broad immunity idea, while later constitutional law became more willing to allow neutral, generally applicable taxes. So Collector v. Day is not just a holding to memorize, it is a marker in the Court’s shift from rigid separation toward a more flexible balance between governments.
If you are tracing federalism doctrine, this case is one of the first stops. It connects directly to how the Supremacy Clause limits state interference and to later questions about when taxes are discriminatory versus merely incidental. That makes it a useful anchor case whenever a problem asks you to spot constitutional limits on state authority.
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Visual cheatsheet
view galleryIntergovernmental Immunity
Collector v. Day is one of the classic cases used to explain this doctrine. The decision shows the basic rule that one government cannot tax or regulate the other in a way that interferes with essential operations. When you see a fact pattern involving a state law affecting federal work, intergovernmental immunity is the first doctrinal label to consider.
Supremacy Clause
The case fits the bigger idea that federal law and federal functions outrank conflicting state action. The Supremacy Clause is not the same thing as intergovernmental immunity, but they often point in the same direction when a state tries to burden the national government. Collector v. Day shows how constitutional supremacy can limit state taxation even without a direct conflict over a statute.
Federalism
This case is a federalism case because it deals with the line between state power and national power. It helps you see federalism as a working structure, not just a division on paper. The Court treated the ability to tax as something that could distort the balance if one sovereign used it against the other.
Tax Immunity
Collector v. Day is often discussed as a tax immunity case because the issue was whether a state could tax federal income. The broader point is that some taxes are not just revenue tools, they can also be forms of control. That is why the Court looked at the effect of the tax on federal authority, not just at the tax label.
A case brief, issue-spotting question, or short essay might ask you to identify whether a state tax on a federal worker is constitutional. The move is to spot intergovernmental immunity, explain that Collector v. Day treated federal salaries as protected from state taxation, and then analyze whether the state action burdens a federal function. If the professor gives you a later case, you may also need to explain that the doctrine has narrowed over time, so not every tax on a federal-related activity gets the same treatment. In a discussion section, you might use the case to compare older broad immunity reasoning with modern, more flexible federalism analysis.
Sovereign immunity usually means the government itself cannot be sued without consent. Collector v. Day is different because it is about one government taxing another government’s operations, not about lawsuits. Both ideas protect governmental independence, but they do so in different legal settings.
Collector v. Day held that a state could not tax the salary of a federal officer.
The case is a foundation for intergovernmental immunity, which protects one level of government from interference by the other.
Its logic comes from federalism, because each sovereign needs room to carry out its own constitutional functions.
The decision reflects an older, broader view of immunity that later constitutional doctrine narrowed.
If you see a state tax aimed at federal work, this is a case you should think about right away.
Collector v. Day is a 1871 Supreme Court case about intergovernmental immunity. The Court said a state could not tax the salary of a federal marshal because that would interfere with federal operations. In Constitutional Law I, it is a classic example of the limits federalism places on state power.
The Court thought the tax would let a state burden the federal government by taxing the compensation of its officers. That would create state control over a federal function, which the Court saw as inconsistent with the Constitution’s structure. The reasoning focused on protecting federal operations, not just protecting one employee’s paycheck.
Not exactly. The case is historically important, but later doctrine narrowed the broad immunity approach. Today, constitutional analysis looks more closely at whether a tax is discriminatory or actually burdens essential federal functions. So Collector v. Day is best remembered as an early foundation, not the whole modern rule.
Use it when the issue is a state tax or regulation that reaches into federal activity. It gives you a concrete case for the idea that one sovereign cannot use its powers to interfere with another sovereign’s core work. If you compare it to later cases, you can show how the doctrine moved from broad immunity toward a more balanced approach.