The Reapportionment Act of 1929 (ch. 28, 46 Stat. 21, 2 U.S.C. § 2a) was a combined census and apportionment bill passed by the United States Congress on June 18, 1929, that established a permanent method for apportioning a constant 435 seats in the U.S. House of Representatives according to each census. The bill neither repealed nor restated the requirements of the previous apportionment acts that districts be contiguous, compact, and equally populated.
It was not clear whether these requirements were still in effect until in 1932 the Supreme Court of the United States ruled in Wood v. Broom that the provisions of each apportionment act affected only the apportionment for which they were written. Thus the size and population requirements, last stated in the Apportionment Act of 1911, expired immediately with the enactment of the subsequent Apportionment Act.
The Act of 1929 gave little direction concerning congressional redistricting. It merely established a system in which House seats would be reallocated to states which have shifts in population. The lack of recommendations concerning districts had several significant effects.
The Reapportionment Act of 1929 allowed states to draw districts of varying size and shape. It also allowed states to abandon districts altogether and elect at least some representatives at large, which several states chose to do, including New York, Illinois, Washington, Hawaii, and New Mexico. For example, in the 88th Congress (in the early 1960s) 22 of the 435 representatives were elected at-large.
The mandate for distributing seats in the United States House of Representatives among the various states according to the most recent decennial census is found in Article One, Section 2, Clause 3 of the United States Constitution. The first federal law governing the size of the House and the method of allotting representatives, the Apportionment Act of 1792, was signed into law by George Washington in April 1792. It set the number of members of the House at 105 (effective March 4, 1793, with the 3rd Congress).
With but one exception, the Apportionment Act of 1842, Congress enlarged the House of Representatives by various degrees following each subsequent census through 1913, by which time the membership had grown to 435. From the 1790s through the early 19th century, the seats were apportioned among the states using Jefferson's method. In 1842, the House was reduced to 223 members by the incoming Whig Party, which had ousted the Jacksonian Democrats.
In 1842 the debate on apportionment in the House began in the customary way with a jockeying for the choice of a divisor using Jefferson's method. On one day alone, 59 different motions to fix a divisor were made in a House containing but 242 members. The values ranged from 30,000 to 140,000 with more than half between 50,159 and 62,172. But the Senate had tired of this approach and proposed instead an apportionment of 223 members using Webster's method. In the House John Quincy Adams urged acceptance of the method but argued vehemently for enlarging the number of members, as New England's portion was steadily dwindling.
From 1842 through the 1860s, the House increased minimally at each census and as new states were admitted to the union. But the Fourteenth Amendment to the United States Constitution dramatically increased the apportionment population of the Southern states because the black population counted fully instead of being reduced to three-fifths its numbers. As a result, a major increase in seats was needed to keep about the same number of seats in the northern states and the House was enlarged by 50 seats (21%) in respect of the 1870 census. The reapportionment of 1872 created a house size of 292. No particular apportionment method was used during the period 1850 to 1890, but from 1890 through 1910, the increasing membership of the House was calculated in such a way as to ensure that no state lost a seat due to shifts in apportionment population. In 1881, a provision for equally populated contiguous and compact single member districts was added to the reapportionment law, and this was echoed in all decennial reapportionment acts through to 1911.
Then, in 1920, the Republicans removed the Democrats from power as the Whigs had done in 1838, taking the presidency and both houses of Congress. Due to increased immigration and a large rural-to-urban shift in population from 1910 to 1920, the new Republican Congress refused to reapportion the House of Representatives with the traditional contiguous, single-member districts stipulations because such a reapportionment would have redistricted many House members out of their districts. A reapportionment in 1921 in the traditional fashion would have increased the size of the House to 483 seats, but many members would have lost their seats due to the population shifts, and the House chamber did not have adequate seats for 483 members. The Reapportionment act of 1929 did away with any mention of districts at all. This provided a solution to the problem of threatened incumbents by allowing the political parties in control of the state legislatures to draw districting lines at will and to elect some or all representatives at large.