Article I, Section 10, Clause 3:

No State shall, without the Consent of Congress, lay any Duty of Tonnage, keep Troops, or Ships of War in time of Peace, enter into any Agreement or Compact with another State, or with a foreign Power, or engage in War, unless actually invaded, or in such imminent Danger as will not admit of delay.

Prior to the Constitution’s enactment, many colonies, and later states, imposed duties of tonnage. While such duties most commonly applied to foreign vessels entering state ports,1 some duties also applied to vessels from other colonies.2 Colonies generally framed these duties as revenue-raising measures to provide for the public defense.3 Because colonies considered these duties to be a potential way to protect and grow their own shipping industries, they often exempted their own ships from the tonnage duties.4 Colonies also used duties of tonnage to retaliate economically when another colony imposed duties, offering to remove the retaliatory duties on a reciprocal basis. For example, Virginia adopted duties of tonnage in retaliation for Maryland’s decision to impose such duties. While Virginia described the duty as “unneighborly,” it insisted that “Maryland vessels must [also be subject to a duty] until [Maryland’s] laws are repealed.” 5

During the Constitutional Convention, the delegates did not consider the question of duties of tonnage until August 1787. The committee considering whether to regulate state authority to impose these duties tabled a report that proposed prohibiting states from requiring vessels to pay duties to access their ports. The Committee concluded that tonnage duties should be “uniform throughout the United States.” 6

When the Constitutional Convention considered the committee’s proposal in September 1787, the delegates debated whether such a clause was necessary and would appropriately balance the powers of the federal and state governments. Some delegates, including James Madison, thought the power to impose duties of tonnage qualified as regulation of trade and therefore fell exclusively within Congress’s general authority to regulate commerce.7 Other delegates, who viewed the Commerce Clause’s language as too vague to determine whether duties of tonnage fell within its scope, argued that the Constitution should expressly allow states to impose such duties in order to pay certain expenses, such as cleaning harbours and constructing lighthouses. Maryland delegates, James McHenry and Daniel Carroll, proposed that “no State shall be restrained from laying duties of tonnage for the purpose of clearing harbours and erecting light-houses.” 8 Another delegate, Gouverneur Morris of Pennsylvania, thought Congress’s power to regulate commerce did not extend to duties of tonnage.9 The Clause’s final text addressed the conflict over the Commerce Clause’s scope and state needs for revenue from duties of tonnage by generally prohibiting states from imposing duties of tonnage unless permitted by Congress. This text was narrowly adopted with six delegations in favour, four against, and one divided.10

Footnotes

1

William W. Bates, American Navigation 32 (1902).

2

Id. at 33.

3

Id. at 34.

4

Id.

5

Id.

6

2 The Records of the Federal Convention of 1787, at 434 (Max Farrand ed., 1911).

7

Id. at 625.

8

Id.

9

Id.

10

Id. at 625–26.