The Constitution specifies that the minimum population size of a congressional district shall be thirty-thousand and, as such, this number provides a benchmark, or a reference point, to what was believed to be an appropriate size for a federal district. However, if not for the events that transpired on September 17, 1787, we would be discussing forty thousand rather than thirty thousand.
“Security for the Rights & Interests of the People”
September 17, 1787, was the final day of the Constitutional Convention in Philadelphia. Two days earlier the convention unanimously agreed to the text of the Constitution and, having since been inscribed on the parchment, it was now ready to be signed by all the delegates present. Despite that, an urgent proposal was made to the assembly by the delegate from Massachusetts who requested, for the purposes of lessening the objections to the Constitution, that the clause declaring “the number of Representatives shall not exceed one for every forty thousand...” might be reconsidered in order to strike out forty and replace it with thirty. After this motion was seconded by others, George Washington rose to address the question. Though he had been the president of the convention, this was the first time Washington addressed the assembly on a substantive matter. According to Records of the Federal Convention, Washington stated that:
“The smallness of the proportion1 of Representatives had been considered by many members of the Convention, an insufficient security for the rights & interests of the people. …and late as the present moment was for admitting amendments, he thought this of so much consequence that it would give much satisfaction to see it adopted.”2
On the strength of Washington’s argument ― that forty thousand was too large to provide sufficient “security for the rights & interests of the people” ― this proposal was then unanimously affirmed. The word “forty” was changed to “thirty” so that the Constitution now declares that the “Number of Representatives shall not exceed one for every thirty Thousand...” ― and with that awkward prose, thirty-thousand became the minimum district size.
Forty-Thousand is too large?
Given that the average size of a congressional district is currently around 700,000, a district of 40,000 may seem rather quaint. However, as explained above, 40,000 was viewed as so large that, fearing it would be rejected by the public, the Founders reduced it to 30,000. How could forty-thousand be considered too large? As illustrated in the chart to the right, in 1787 the constituency sizes of the representatives in the state legislatures ranged from 1,012 to 6,032.3 Given that, it easy to see why the general public would have to be persuaded to accept even the smaller 30,000-person districts.
Selling the Constitution
After the Constitution was proposed, a series of editorials were published in order to generate popular support. Now known as the “Federalist Papers”, these treatises elaborated on the many virtues of the Constitution and offered defenses against criticisms. Relative to the large congressional districts, Federalist 56 argued that because the “objects of federal legislation” were to be limited to a few areas, “a moderate number of representatives” would be sufficient. Clearly, the “objects” of federal legislation have since become boundless, but that is a different subject.
Returning to the main subject, in two of the Federalist Papers “thirty-thousand” was presented as an absolute ratio without any hint that it was merely a minimum! Federalist 56 declared that “...it seems to give the fullest assurance, that a representative for every THIRTY THOUSAND INHABITANTS will render the [House of Representatives] both a safe and competent guardian of the interests which will be confided to it.” Not only was this absolute assurance provided, but “thirty thousand” was entirely capitalized (just as quoted above).
The Bill of Rights
Fortunately, the members of the states’ conventions (which convened to evaluate the proposed Constitution) noticed the indefiniteness of the Constitution’s “shall not exceed” language. For example, Melancton Smith (delegate to the New York convention) observed in June of 1788 that it is “a power inconsistent with every principle of a free government, to leave it to the discretion of the rulers to determine the number of representatives of the people. There was no kind of security except in the integrity of the men who were intrusted; and if you have no other security, it is idle to contend about constitutions.”4
Consequently, this became the most contentious issue debated during the states’ ratification conventions. For example, 30% of the New York convention’s 85,000-word transcript was devoted exclusively to this subject! Moreover, of the six state conventions that endorsed various amendments to the Constitution, five proposed an amendment that would require a minimum number of representatives (to complement the maximum resulting from the Constitution’s “one for every thirty Thousand”).
On June 8, 1789, James Madison proposed a set of amendments for the Bill of Rights which “were a distillate of the proposals emanating from the state conventions”. The second amendment proposed in his long list was to establish a maximum district size to complement the minimum district size. In fact, as explained in “The Minimum and Maximum Size of the U. S. House of Representatives”,5 Madison had originally proposed that the maximum district size be thirty thousand ― there’s that number again!
The Name Tells a Story
With current district sizes averaging 700,000 and growing, 30,000 provides a reference point against which we can measure how far our government has drifted from being a truly representative democracy. Safe within their imperial-sized districts, most representatives have become dismissive (if not disdainful) of we the people. The reason for this is simple: the huge cost of campaigning in massive districts ensures that the incumbents are accountable only to the special interests that finance their campaigns, but not to us inconsequential citizens. Imagine how accessible and accountable our elected representatives would be if we lived in districts with total populations much closer to the Founders’ vision of thirty-thousand.
 By “smallness of the proportion”, Washington is referring to the ratio of 1:40,000 (which equates to 1/40000 or 0.0025%); that is a smaller proportion than 1:30,000 (which equates to 1/30000 or 0.0033%).
 Records of the Federal Convention (Farrand’s Records) pages 643-644.
 This is the average number of people per legislator in the lower house of the state’s assembly. For additional information see the TTO Information Brief: “Average Number of Residents per Representative circa 1787”.
 June, 1788. Source: New York Debates: Quotes Regarding the Size of the House of Representatives
 Supporting citations for this section can be found in the TTO report titled “The Minimum and Maximum Size of the U. S. House of Representatives” which can be downloaded from this page.
If you have any questions or wish to comment on this post, please visit Thirty-Thousand.org's forum. Also, many commonly asked questions are answered on TTO's home page (see the Question & Answer section).