I recently obtained the records of what may be the last convention of states ever held—records demonstrating that states were meeting in convention well into the mid 20th century.

A “convention of states” as the American Founders and subsequent generations understood the term, is a temporary conclave of legislatively-authorized representatives from three or more states. It is both a diplomatic gathering—the representatives or “commissioners” are essentially ambassadors from their respective legislatures—and a problem-solving task force. Sometimes representatives of sovereignties other than states, such as Indian tribes or the federal government (or, in colonial times, the British crown), have been invited to participate. Conventions of states also have been called “committees of states,” “congresses,” and “commissions.”

Conventions of states, both national (“general”) and regional (“partial”), have met for many different purposes: to plan common defense, work out common responses to political challenges, negotiate treaties with Indian tribes, seek and propose solutions to economic problems, propose constitutional amendments, and, on two occasions (Philadelphia in 1787 and Montgomery in 1861) to prepare new constitutions. Only the last two can properly be called constitutional conventions.

In the 20th century, states used them to hammer out western water compacts. I previously reported on the Santa Fe Convention of 1922, formally called the Colorado River Compact Commission. It was the gathering of seven states and a federal commissioner, then-Secretary of Commerce Herbert Hoover.  It negotiated the Colorado River Compact. I also have reported that similar gatherings met to negotiate the Rio Grande River Compact and an abortive North Platte River compact. My latest acquisition is the official record of the convention that negotiated the compact covering the Upper Colorado River —the portion north and east of Lee Ferry, Arizona.

This was a true convention among five states: Arizona, Colorado, New Mexico, Utah, and Wyoming. It met intermittently from July 22, 1946 to August 5, 1949. Commissioners attended from each state. They were not chosen by their legislatures directly, but legislative statutes authorized the appointment of each and gave each his power. At the request of the states, President Truman named a federal representative to participate as well: Harry W. Bashore, formerly Commissioner of the U.S. Bureau of Reclamation.

The group’s assignment was to divide up the waters of the Upper Colorado River among the five states and determine how much each state had to provide to the states of the Lower Colorado River. This was a highly technical task. Accordingly, unlike most conventions (but like the Santa Fe meeting) there was only one commissioner from each state, but each was assisted by a technical staff. In addition, the group created an engineering advisory committee and a legal advisory committee. The technical nature of the job was why the group had to keep adjourning and reassembling: Engineering studies and negotiations over local streams were performed in the interim.

Another interesting variation is that, like the 1922 convention, the Upper Colorado River group met in different cities and towns at different times: Cheyenne, Wyoming; Denver, Colorado; Salt Lake City and Vernal, Utah; and Santa Fe, New Mexico. In addition, it held public hearings in four other towns. In all, there were 41 days of sessions grouped into eleven formal “meetings.” The first eight meetings led to completion of the compact in 1948. The remaining three, held the following year, were short sessions for wrapping up business.

The conclave also gave itself a name, since its authorizing documents didn’t specify one. It called itself the Upper Colorado River Basin Compact Commisssion.

Within those variations, the group operated according to standard convention of states protocols. Specifically:

* The commissioners established their own procedures. Thus, they made it clear that a preliminary meeting that included the state governors did not bind them, and they re-voted on the decisions made at that preliminary meeting.

* Each state had one vote, cast by its commissioner, no matter how many people from each state happened to be present. After briefly considering a unanimity rule (such as the Colorado River Commission adopted but eventually abandoned), the group retained a rule of decision by a majority. However, it strove for unanimity, and generally was successful. The federal representative had no vote.

* The commissioners elected their own officers: As has been typical among interstate conventions the chairman was a commissioner and the secretary was not. Although he could not vote, Mr. Bashore was elected chairman.

* The record reproduces many roll call votes by states, some quite dramatic. The voting usually was open. But the vote on the overall percentages by which states would divide the river water was by secret ballot.

* The commissioners affirmed that they were negotiating by virtue of the states’ reserved sovereign powers, not by virtue of permission of federal law (as President Truman seemed to think). In this respect, the Upper Colorado River Convention was typical—although a gathering held under Article V would derive its authority from the Constitution rather than from reserved sovereign power.

The proceedings the Upper Colorado River Basin Compact Commission are impressive. The commissioners and staff worked very hard. Most people involved were thoughtful and highly qualified. The engineering studies were voluminous.

Also impressive is the recurrence of some important names. A listed adviser was Ralph Carr, who later as governor of Colorado during World War II, won national attention by opposing the Roosevelt administration’s groundless incarceration of Japanese-American citizens. Another listed adviser was Barry M. Goldwater, later U.S. Senator and the 1964 Republican nominee for President.

The compact the convention negotiated was approved by all five states and by Congress. It is still in effect. It created a permanent administrative body called the Upper Colorado River Commission, to whose staff I am grateful for loaning me the convention record.