It’s trivia I never wondered about, but when I saw an article on Cleveland.com regarding the most common 15 last names in the United States I suddenly had to know. Photo by Cytonn Photography on Unsplash person writing on white paperI knew it used to be names like Washington and Smith. These names were derived from census data and sure enough, since the 2000 census six Hispanic last names are now among the 15 most common in the United States. Photo by Erik Mclean on Unsplash a close up of an old fashioned typewriterSo what are the top 15 most common last names in the country? AndersonLOOK: Baby boomer baby names that have gone out of style Using info from the Social Security Administration's baby name database, Stacker compiled a list of baby boomer baby names that have declined in popularity.