1940 United States census

The 1940 United States census, carried out by the Census Bureau, counted 132,164,569 people living in the United States. This was an increase of 7.6 percent from the 1930 population of 122,775,046 people. The official day for the census was April 1, 1940.

This census asked new questions, such as where people lived five years earlier, their highest level of education, and information about their wages. It also used a special method called sampling, where one in every twenty people received extra questions on their census form. Other new ideas included testing the census method in 1939. This was the first time every state (there were 48 states) had more than 100,000 people. It was also the first census to include a “long form” with more detailed questions about jobs and homes, which was later used until the 2000 census before being replaced by the American Community Survey.

Census questions

The 1940 census asked people about their homes, jobs, age, education, and birthplace. Some people were also asked extra questions, like when they first got married. You can learn more about the 1940 census from the Integrated Public Use Microdata Series.

Data availability

After the census was done, the original papers were turned into microfilm and then destroyed.

Because of rules, private details from the census were kept secret for 72 years. After that time, information that does not tell who the people were became available to everyone through the Integrated Public Use Microdata Series. Data for smaller places and maps can also be downloaded from the National Historical Geographic Information System.

On April 2, 2012—exactly 72 years after the census—microfilm copies of the forms were made public by the National Archives and Records Administration. At first, the records could only be found by enumeration district, but several groups are working to make easier ways to search them, sometimes by using crowdsourcing.

State rankings

Rank	State	Population as of 1940 census	Population as of 1930 census	Change	Percent change
1	New York	13,479,142	12,588,066	891,076	7.1%
2	Pennsylvania	9,900,180	9,631,350	268,830	2.8%
3	Illinois	7,897,241	7,630,654	266,587	3.5%
4	Ohio	6,907,612	6,646,697	260,915	3.9%
5	California	6,907,387	5,677,251	1,230,136	21.7%
6	Texas	6,414,824	5,824,715	590,109	10.1%
7	Michigan	5,256,106	4,842,325	413,781	8.5%
8	Massachusetts	4,316,721	4,249,614	67,107	1.6%
9	New Jersey	4,160,165	4,041,334	118,831	2.9%
10	Missouri	3,784,664	3,629,367	155,297	4.3%
11	North Carolina	3,571,623	3,170,276	401,347	12.7%
12	Indiana	3,427,796	3,238,503	189,293	5.8%
13	Wisconsin	3,137,587	2,939,006	198,581	6.8%
14	Georgia	3,123,723	2,908,506	215,217	7.4%
15	Tennessee	2,915,841	2,616,556	299,285	11.4%
16	Kentucky	2,845,627	2,614,589	231,038	8.8%
17	Alabama	2,832,961	2,646,248	186,713	7.1%
18	Minnesota	2,792,300	2,563,953	228,347	8.9%
19	Virginia	2,677,773	2,421,851	255,922	10.6%
20	Iowa	2,538,268	2,470,939	67,329	2.7%
21	Louisiana	2,363,516	2,101,593	261,923	12.5%
22	Oklahoma	2,336,434	2,396,040	−59,606	−2.5%
23	Mississippi	2,183,796	2,009,821	173,975	8.7%
24	Arkansas	1,949,387	1,854,482	94,905	5.1%
25	West Virginia	1,901,974	1,729,205	172,769	10.0%
26	South Carolina	1,899,804	1,738,765	161,039	9.3%
27	Florida	1,897,414	1,468,211	429,203	29.2%
28	Maryland	1,821,244	1,631,526	189,718	11.6%
29	Kansas	1,801,028	1,880,999	−79,971	−4.3%
30	Washington	1,736,191	1,563,396	172,795	11.1%
31	Connecticut	1,709,242	1,606,903	102,339	6.4%
32	Nebraska	1,315,834	1,377,963	−62,129	−4.5%
33	Colorado	1,123,296	1,035,791	87,505	8.4%
34	Oregon	1,089,684	953,786	135,898	14.2%
35	Maine	847,226	797,423	49,803	6.2%
36	Rhode Island	713,346	687,497	25,849	3.8%
—	District of Columbia	663,091	486,869	176,222	36.2%
37	South Dakota	642,961	692,849	−49,888	−7.2%
38	North Dakota	641,935	680,845	−38,910	−5.7%
39	Montana	559,456	537,606	21,850	4.1%
40	Utah	550,310	507,847	42,463	8.4%
41	New Mexico	531,818	423,317	108,501	25.6%
42	Idaho	524,873	445,032	79,841	17.9%
43	Arizona	499,261	435,573	63,688	14.6%
44	New Hampshire	491,524	465,293	26,231	5.6%
—	Hawaii	422,770	368,300	54,470	14.8%
45	Vermont	359,231	359,611	−380	−0.1%
46	Delaware	266,505	238,380	28,125	11.8%
47	Wyoming	250,742	225,565	25,177	11.2%
48	Nevada	110,247	91,058	19,189	21.1%
—	Alaska	72,524	59,278	13,246	22.3%
—	United States	132,165,129	123,202,660	8,962,469	7.3%

City rankings

Locations of 50 most populous cities

This part shows the 50 biggest cities in the United States by how many people lived there in 1940. The map has important cities like New York, Chicago, Philadelphia, Detroit, and Los Angeles, and more. Some cities, like Manila in the Philippines, are not on the map.

Use for Japanese American internment

During World War II, the Census Bureau shared information from the 1940 census with government agencies. This information helped organize the moving of many Japanese American families at that time. A U.S. Army leader later said that the 1940 census was a very important source of information before this happened.