When I was studying for the ministry in Fort Wayne, Indiana, I worked as a delivery man. My route included two different towns called Edgerton: one in Indiana, tight against the Ohio border, in the next county to the south of Fort Wayne; and one in Ohio, equally close to the state line, lying even closer to Fort Wayne to the northeast.
A couple years later, I graduated from the seminary and accepted my first call to be a pastor. My parish was in the northern part of the Kansas City metropolitan area. One of the towns in my parish, north of Kansas City and only a handful of miles from the Kansas border, was little Edgerton, Missouri. I couldn't help but notice, however, that in the southern reaches of the metro area, situated about equally far from the city center and the state line, is the small town of Edgerton, Kansas.
From these coincidences, I formed some superstitious ideas in my mind, ideas about towns called Edgerton. First, I decided that there must be an Edgerton in every state of the U.S. Second, in honor of the "edge" part of its name, each Edgerton must be close to the edge of the state to which it belongs. Third, I predicted that one might find pairs of Edgertons huddling together with little more than a state line between them. Fourth, I recognized that all Edgertons must be very small towns, possibly on the edge of being unincorporated villages; perhaps not appearing on every map.
Of course, these notions were all wrong. It was, after all, sheer coincidence that I happened to live so close to four Edgertons. Thanks to Wikipedia, I can now convey the sober fact that only three other towns called Edgerton have been found in the United States. That put paid to my first theory. The second theory fails on the grounds that Edgerton, Wyoming, is near the center of the state; besides which, such towns are mainly named after a historic figure, such as Alonzo J. Edgerton, who played a role in the 19th century politics of both Minnesota and South Dakota. This may also explain why Edgerton, Minnesota, is close to the South Dakota border, removing it as far as possible from Wisconsin, where the seventh and last Edgerton hovers above the Illinois line in an almost equal display of indifference to its soulmate in Minnesota. So much for my third theory, about Edgertons going in pairs! The only thing saving my theories from complete extinction is the possibility that Theory No. 4 is true, and that there are other Edgertons out there, too tiny and insignificant for Wiki to take notice.
Other town-names are much more common. Take Centerville, for instance. Twenty-two states have towns by that name; plus Michigan has a Centerville Township. At present California has no fewer than seven Centervilles; at least two more examples of Centerville, CA have vanished off the map. Ohio and Pennsylvania each have two Centervilles. If you allow for spelling variants, seven states currently have towns called Centreville; Pennsylvania used to have two, but they've both changed their names. Canada also has six towns named Centreville, and an amusement park besides. I've never been in or near any of these Centervilles (or Centrevilles), but as far as I can tell from looking at maps, few of them are located near the center of their respective states. Go figure.
I have lived in one of this nation's Irontons, the one in Minnesota. Fourteen towns in the U.S. are officially known as Ironton, and one (in Alabama) is unofficially so. Twenty-three states have a town called Rockville, plus New York has a Rockville Centre. There are Nashvilles in 13 states; plus a Nashville Plantation (in Maine), a Nashville Township (in Minnesota), and a second Nashville (unincorporated) in Indiana. The only one I have visited is Indiana's incorporated city of Nashville, in one of that state's beauty spots, Brown County.
There are towns called Bloomington in twelve states, and townships by that name in seven (including two in Iowa); Canada has three more, and Ohio has a New Bloomington to spice things up. I am only personally acquainted with the Bloomingtons in Illinois, Indiana, and Minnesota, the three largest and best-known cities of that name.
Of cities named Defiance, the U.S. has only four: in Iowa, Missouri, Ohio, and Pennsylvania. They're hardly worth mentioning, except that I've been in three of them. Maybe I should make a pilgrimage to PA so I can complete the set. There are also four cities called Manhattan (not counting the borough of NYC); three called Minneapolis; thirteen or fourteen St. Pauls besides the capital of Minnesota (to say nothing of numerous foreign cities named after that saint); thirteen Houstons besides the one in Texas (plus one each in the U.K. and Canada); and seventeen U.S. cities named Columbus besides the capital of Ohio. This last figure goes up if you include Columbus City and Columbus Junction (IA) and Columbus Grove (OH).
There are nine Cedarvilles in the U.S., plus two in Canada and one in South Africa. There are twelve Rivertons in the U.S., two each in Canada and Australia, and one each in New Zealand and South Africa (though the latter is only a resort). At least 19 American towns (considerably more if you count unincoporated areas) are known as Riverside; so are three towns in the U.K. I count five American and two Canadian towns called Lakeville. There are at least a dozen Lakesides in the U.S. and several more in Canada and the U.K.
At least 14 cities in the U.S. bear the name Mexico, 12 are called Vienna, and 15 are called Paris; 20 American towns are named Berlin, if you count the ghost town in Nevada. Woodville is currently the name of 16 towns in the U.S., four of them in North Carolina; half a dozen more are scattered between Canada, Australia, New Zealand, and the U.K.
One can find eight towns called Greensboro in the U.S., of which the most notable is in North Carolina. Twelve states have a town called Wayne in them, not including my dear Fort Wayne. Thirteen states have a city, town, or village named Decatur, seven of which are county seats. I have had good times in three Decaturs: stopping on a choir tour in Decatur, Illinois; doing field work as a seminarian at Decatur, Indiana; and admiring the view of Decatur, Nebraska, in my rear-view mirror while crossing the bridge into Iowa. There are twenty towns called Danville in the U.S., two of them in Maryland; Canada, Ireland, and South Africa also have one each.
Fully 28 states have a city named Washington, precisely speaking; this is, of course, in addition to our nation's capital. Other towns named after our nation's first president include Washington Boro and Washington Crossing (PA), Washington Court House (OH), Washington Grove (MD), Washington Mills (NY), Washington Park (IL, NJ, and NC), Washington Terrace (UT), Washingtonville (NY and OH), and Washington-on-the-Brazos (TX). In addition, at least a dozen other countries have a city named Washington. These include two in England, one in Canada, one in Ireland, and one in South Africa; the rest are spread among Caribbean and Latin American countries. The Philippines has a New Washington, Jamaica a Washington Gardens, and Brazil a Washington Luiz.
Nevertheless, while I was living in Washington, Missouri, I found it hard to convince some people that any city by that name could be allowed to exist outside the District of Columbia. These were typically the same idiots who, when I identified myself by phone, would ask me how to spell my four-letter, phonetically-spelled last name.
Another founding father who has given his name to a bevy of towns is Madison, author of our constitution and namesake of 25 American municipalities (not counting Madison Lake, MN). The most notable example is the capital of Wisconsin, where I once enjoyed a good pub-crawl with a bridegroom and his groomsmen. I also have some interesting memories of Madison, Nebraska - including the day I spent there while my stepfather was trying to hide me from my father. Good times.
There are at least 25 cities called Cleveland in the U.S., of which the one in Ohio is only the biggest and best-known. Two of them are in North Carolina; five (!) are in Wisconsin. They can't all be named after two-time U.S. President Grover Cleveland; after all, the name goes back much farther in history, all the way to England, where there used to be a county called Cleveland. Canada and Australia also have two cities by that name, each.
Jefferson is the name of at least 17 towns and cities in the U.S. and one in Canada. None of them amount to much; but then there is Jefferson City, the capital of Missouri. There are at least 23 U.S. towns called Monroe, two each in Wisconsin and Indiana. Allowing for spelling variations, there are 16 towns called Lafayette (or La Fayette, or LaFayette, etc.) in the U.S. Most of the dozen or so cities known as Fayette are named after the same man; ditto the dozen or so cities of Fayetteville. That old marquis was probably the most named-after; but when it's a question of identically named towns, the winner seems to be Franklin, with 39 American cities named in his honor. There are four of them in California, two each in New York and Pennsylvania, and six in Wisconsin! Even the Canadian province of Quebec has a Franklin.
One of my idle ambitions has often been to sample all the towns in such a class. You know, like a cheese flight or a wine tasting, only with towns that have the same name. Make a vacation of it. See the country. Take pictures. Visit their historical museums. Keep mementos and make notes. Perhaps write a quirky essay, or perhaps a book, about the experience. It's a silly idea, but it appeals to me anyway. And I'm already four-sevenths of the way through my Edgerton flight.
EDIT: How can I forget my own city of Saint Louis? There are only two other cities by that name in the U.S. - in Michigan and Oklahoma. Give or take a hyphen (used in French nomenclature), one may also find four municipalities so named in France, three in Canada, and three in or around the continent of Africa - of which only the one in Senegal is a world traveler's destination.