A single-member district refers to an electoral district represented by one legislative representative. Members of the U.S. House of Representatives have been elected exclusively from single-member districts since the 92nd Congress (1971-1973), when legislation mandating their use came into effect (P.L. 90-196; 2 U.S.C. §2c). In prior sessions, some Members were elected from multimember districts (also referred to as plural districts), which are geographically defined districts electing more than one representative; or in general ticket elections, whereby a state elected all of its representatives at large without geographically defined districts (see CRS In Focus IF12568, Election Policy Fundamentals: At-Large House Districts). This In Focus provides information about the historical use of single-member districts and the legislative context for 2 U.S.C. §2c, as well as subsequent proposals that might provide for the use of multimember districts.
Constitutional Provisions and Context
Though the Constitution itself is silent on the issue, according to political scientist Jay K. Dow, some founders envisioned a House of Representatives made up of Members elected from single-member districts. James Madison, for example, made reference to representation of specific geographic constituencies in Federalist Papers 56 and 57, and Alexander Hamilton and George Mason also referenced such districts at the New York ratifying convention and the Constitutional Convention, respectively.
Under the Constitution (Article 1, Section 2, as amended by Section 2 of the Fourteenth Amendment), Congress apportions House seats across states by population after every decennial census. Article 1, Section 2 also—without directly mentioning House districts—implies a minimum district size with its requirement that there can be no more than one Representative for every 30,000 persons (provided that each state receives at least one Representative). Congress also holds the authority to alter state regulations pertaining to "The Times, Places and Manner" of House elections.
House Districts in Early Congresses
During the late 1700s and early 1800s, states with multiple House seats varied in whether, or how, districts were used in House elections. In the 1st Congress, for example, seven such states used single-member districts and four states elected representatives at-large. According to historian Rosemarie Zagarri, 31% of total House membership between 1789 and 1842 was elected from states using multimember districts.
As part of the apportionment act of 1842, the Whig-controlled Congress included language requiring states to use single-member districts. Other election practices, such as multimember districts and general ticket elections, had often provided uniform Democratic Party control of several state congressional delegations. The act specified that Representatives from states apportioned multiple seats
shall be elected by districts composed of contiguous territory equal in number to the number of Representatives to which said State may be entitled, no one district electing more than one Representative.
The use of general ticket elections, however, continued in practice after 1842; four states elected their delegations to the 28th Congress (1843-1845) through the general ticket system, and the new Democratic majority seated these delegations. In 1967, general ticket elections, and any electoral arrangement other than single-member districts, were eliminated by P.L. 90-196, as discussed below.
Legislative Background for 2 U.S.C. §2c
Prior to the 20th century, Congress passed apportionment legislation intended to apply only for a single census or apportionment. Various apportionment acts since 1842 had imposed certain conditions on congressional districts (e.g., that they be geographically compact, be contiguous, or have equal populations; see CRS Insight IN11618, Congressional Redistricting Criteria and Considerations). Some of these decennial laws included similar language to the 1842 apportionment act; others did not.
The apportionment act of 1911 contained language similar to the 1842 act, specifying that any state with multiple House seats would have a number of districts equal to its number of Representatives, and each district would elect no more than one Representative. The 1911 act also specified that those districts should be compact, contiguous, and with equal populations.
The apportionment act of 1929, however, imposed no such districting language, enabling the use of general ticket elections and at-large districts alongside geographic single-member districts for several apportionments starting in 1932. The 1929 act, amended by legislation in 1941, established a general reapportionment formula and process that could repeat across decades. No further legislation addressing congressional redistricting or apportionment was enacted until 1967.
For several years beginning in the 1950s, Representative Emanuel Celler of New York introduced legislation that would have affected congressional redistricting. Celler's bills would have required certain district criteria (such as compact and contiguous districts with limited population variance across districts within a state). Later versions of his bills, beginning with H.R. 8329 in the 84th Congress (1955-1957), also included provisions that would have required the use of single-member districts for the House, with language similar to the 1842 apportionment act. These redistricting bills began to receive further attention in Congress by the mid-1960s, beginning with House passage of H.R. 5505 in the 89th Congress.
In the late 1960s, following the passage of the Voting Rights Act of 1965 and various Supreme Court cases regarding population equality in congressional districts (see CRS In Focus IF12250, Congressional Redistricting: Key Legal and Policy Issues), some supporters of civil rights legislation viewed a single-member district mandate as a related reform. Single-member districts, from their perspective, could prevent the dilution of minorities' votes through the use of at-large districts and general ticket elections, which were still in use in several states. Additionally, some were concerned that courts would require the use of at-large districts in situations where a state's redistricting was not found to be in compliance with "one-person, one-vote" population equality requirements.
Representative Celler's redistricting legislation was reintroduced as H.R. 2508 in the 90th Congress (1967-1969) and received considerable attention in both chambers. Some Members sought to provide guidance to state legislatures regarding redistricting practices, and some sought to reduce the frequency of judicial involvement in congressional redistricting. In Wesberry v. Sanders (1964) and other contemporary decisions, the Supreme Court had struck down certain districts based on the "equality standard" or the principle of "one person, one vote." Among other provisions, some early versions of H.R. 2508 proposed establishing permissible levels of population variance across a state's congressional districts.
Some civil rights proponents thought that the provisions in H.R. 2508 would allow for too great a variance in district size, and believed that this could lead to the dilution of urban and minority votes. Speaking against the bill during its Senate floor consideration, Senator Robert F. Kennedy said that
Court-supervised adherence to the principles of equal representation all across our nation would probably increase significantly the number of congressmen who are closer to and more responsive to the interests of large urban minority groups. Delay in achieving fair apportionment will perpetuate this underrepresentation.... The confusion and litigation which H.R. 2508 will surely spawn is of far more than abstract significance—it will cause a delay in the realization of a constitutional right for millions of Americans.
Passed by both chambers, the bill went through two conference committees and had several provisions removed as the House and Senate attempted to reach a compromise. The House agreed to conference report provisions provided in H.Rept. 795 on October 26, 1967, which would have (1) required use of single-member districts for all states (with short-term exceptions for Hawaii and New Mexico, the two states using at-large districts at the time), and (2) prohibited any redistricting prior to 1970 unless a special census was taken to update apportionment population counts. The Senate never agreed to this version of the bill.
It was in this context of legislative impasse that single-member district proponents quickly amended a private bill, H.R. 2275, An Act for the Relief of Doctor Ricardo Vallejo Samala, to include the Uniform Congressional District Act. This mandated single-member districts but did not address other aspects of redistricting, the disputes over which had led to the failure to pass earlier legislation. States using at-large districts at the time, New Mexico and Hawaii, were allowed to retain these districts temporarily. The legislation passed a few weeks later, and was signed by President Lyndon Johnson in December 1967. It was codified as 2 U.S.C. §2c.
Contemporary Considerations
Congress maintains an ongoing interest in features of the U.S. electoral system and their implications for representational democracy. In recent decades, legislation has been introduced to modify or eliminate the single-member district mandate, including the Voters' Choice Act (H.R. 2545, 104th Congress; H.R. 3068, 105th Congress; H.R. 5679, 106th Congress; and H.R. 1189, 107th Congress), the States' Choice of Voting Systems Act (H.R. 1173, 106th Congress), and the Fair Representation Act (H.R. 3057, 115th Congress; H.R. 4000, 116th Congress, and H.R. 3863, 117th Congress). Electoral system features can often be interrelated, and this proposed change is often paired with other modifications, such as the allowance of proportional representation or ranked-choice voting. None of this legislation has advanced past the point of introduction.
Some states also utilize different methods for their own legislative elections. Multimember districts are currently used in the Arizona, Idaho, Maryland, New Hampshire, New Jersey, North Dakota, South Dakota, Vermont, and Washington state legislatures.
Some proponents of multimember districts argue that, in conjunction with other electoral reforms, they could allow for greater representation of minority groups who might not command the majority of the vote in a single-member district. By contrast, some supporters of single-member districts, such as Dow, argue that single-member districts allow for "citizens of different backgrounds and political interests [to be] placed in the same political community and have to engage these differences locally rather than nationally," and that single-member districts advance the representation of minority voices.