Granted, it doesn’t tell you everything, as your paternal surname is only part of your ancestry. (You have four grandparents, eight great-grandparents, sixteen great-great-grandparents, etc). But lists of the most common surnames does tell you something.
The U.S. Census Bureau released the most common surnames in the U.S. according to the 2010 Census. As reported at the Daily Caller, six of those surnames are Spanish:
Six Hispanic surnames were among the top 15 common last names in 2010, according to figures released by the U.S. Census Bureau Thursday [December 15th].The article includes a chart with three columns containing the most numerous surnames in the past three censuses: 1990, 2000 and 2010. This shows you how rapidly the change is taking place.
By Alex Pfeiffer, Daily Caller, December 15, 2016
In the 1990 census, the fifteen most common surnames were all English: Smith, Johnson, Williams, Jones, Brown, Davis, Miller, Wilson, Moore, Taylor, Anderson, Thomas, Jackson, White, Harris.
(Brown and White are two of my ancestral surnames).
In the 2000 census, four Spanish surnames were in the Top Fifteen list. Garcia was at #8, Rodriguez at #9, Martinez at #11, and Hernandez at #15. Moore, Jackson, White and Harris had dropped off the Top Fifteen.
Now, in the 2010 census, there are six Spanish surnames. Garcia was at #6, Rodriguez at #9, Martinez at #10, Hernandez at #11, Lopez at #12, Gonzalez at #13. Taylor and Thomas had dropped off the Top Fifteen.
Smith, Johnson and Williams remained at #1,#2, and #3 respectively throughout all three lists.
The Daily Caller article also contains this information:
The Census Bureau also released the last names with the largest increase in frequency of use from 2000 to 2010. These are in descending order: Zhang, Li, Ali, Liu, Khan, Vazquez, Wang, Huang, Lin, Singh, Chen, Bautista, Velazquez, Patel, and Wu. There were fewer than 50,000 Zhangs in the United States in 2000 and now there are nearly 100,000. Nearly one in four newborn Americans are the children of immigrants and despite much focus on Latin America immigration, India, China, and the Philippines were among the top countries of origin for immigrants to the U.S. between 2010 to 2014.Also on the topic of surnames, I invite readers to see my previous article entitled What's In A (Sur)Name? Plenty, If You're Planning An Amnesty .
Back in Britain, Smith is still the most common surname in England and Scotland. In Greater London, however, Smith is #2, edged out by Brown. But the third most common surname in Greater London is Patel, an Indian (primarily Gujarati) surname. Khan is #10, Ali is #17, and Rodriguez is #23.