Are you thinking of naming a girl child in the next few months, but do not want to choose the same name as everyone else in the USA? Do you have a penchant for administrative data presented in a pretty and epileptic-fit-inducing form? If you answered yes to either or both of those questions, then this article and its accompanying gif (graphics interchange format) will be for you! The Atlantic has republished a map of the USA which shows you the most popular names for baby girls in each state for each year from 1960.  The dominant name over the entire country is given a colour and then each state where that name is the most popular is also coloured.  Very quickly, you realise that there is very little diversity - the most popular name nationally is usually the most popular for all of the states as well. 
As the years tick by in the gif map (built in Adobe Illustrator using data from the Social Security Administration) it looks like you are watching successive waves of eponymous invaders. “Oh my gosh, the Emily’s have landed in the North East! And they’ve swept across to the Pacific Coast! But now there’s an insurrection in the deep South – the Ashley’s are making inroads into the Emily empire...” I imagine that a gif showing the waves of barbarian invasions across the Western Roman Empire in the fifth century would look similar. The only exception to the trend of quickly established and short-lived name-hegemonies is Jennifer.  Jennifer dominates the American continent for a decade-and-a-half from 1970 onwards before eventually succumbing to the Ashley and Jessica counter-attacks. 
Do you have a "common" name? For example, my brother was one of three or four Timothys in his class at primary school. On the other hand I am always surprised to meet another Marcus. Although at university I've usually taught at least one Marcus each year (out of about 200 students).  Why do names come and go in popularity? Why are some so long lived and indeed timeless?