America's largest ancestry groups in 2010

German-Americans remain the largest ancestral group in the United States according to the US Census Bureau's American Community Survey. Almost 48 million Americans claim German ancestry, or 15.5% of the total population. Keep in mind that 120 million Americans were classified as "Other" ancestral groups, and another 36 million reported no ancestry.

Note that ancestry refers to a person’s ethnic origin or descent, "roots," or heritage, or the place of birth of the person or the person’s parents or ancestors before their arrival in the United States. Some ethnic identities, such as "German" or "Jamaican," can be traced to geographic areas outside the United States, while other ethnic groups such as "Pennsylvania Dutch" or "Cajun" evolved in the United States.

Here is the list of the 50 largest American ancestries in 2010:

Rank	Ancestry	United States Estimated Population	Percentage of Total Population
	Total:	309,349,689	100.0%
1	German	47,901,779	15.5%
2	Irish	34,669,616	11.2%
3	English	25,926,451	8.4%
4	American	19,975,875	6.5%
5	Italian	17,235,941	5.6%
6	Polish	9,569,207	3.1%
7	French (except Basque)	8,761,496	2.8%
8	Scottish	5,460,679	1.8%
9	Dutch	4,645,131	1.5%
10	Norwegian	4,470,081	1.4%
11	Swedish	4,088,555	1.3%
12	European	3,616,843	1.2%
13	Scotch-Irish	3,257,161	1.1%
14	Russian	2,971,599	1.0%
15	French Canadian	2,042,808	0.7%
16	Welsh	1,793,356	0.6%
17	African	1,676,413	0.5%
18	Czech	1,525,187	0.5%
19	Hungarian	1,501,736	0.5%
20	Portuguese	1,405,909	0.5%
21	Danish	1,375,506	0.4%
22	Greek	1,315,775	0.4%
23	British	1,181,340	0.4%
24	Jamaican	965,355	0.3%
25	Swiss	961,380	0.3%
26	Ukrainian	939,746	0.3%
27	Haitian	881,488	0.3%
28	Slovak	762,030	0.2%
29	Austrian	722,282	0.2%
30	Canadian	717,390	0.2%
31	Lithuanian	660,071	0.2%
32	Finnish	647,697	0.2%
33	Scandinavian	570,696	0.2%
34	Lebanese	501,988	0.2%
35	Eastern European	489,534	0.2%
36	Armenian	474,559	0.2%
37	Iranian	463,552	0.1%
38	Romanian	447,293	0.1%
39	Croatian	411,427	0.1%
40	Brazilian	361,814	0.1%
41	Belgian	360,912	0.1%
42	Pennsylvania German	332,341	0.1%
43	Yugoslavian	326,576	0.1%
44	Czechoslovakian	304,020	0.1%
45	West Indian	299,010	0.1%
46	Arab	290,893	0.1%
47	Northern European	282,953	0.1%
48	Nigerian	259,058	0.1%
49	Other Arab	223,020	0.1%
50	Guyanese	214,315	0.1%

Source: U.S. Census Bureau, 2010 American Community Survey

B04006 People Reporting Ancestry, 1 year estimates