The names of places across the world and in particular across the United States are not unique. This may cause confusions, imagine buying a plane ticket from Illinois to Portland in Maine instead of Portland in Oregon - these two cities are on the opposite coasts! The list of all the cities in the US seemed too large to sift through in my limited available time, so I wondered how common are common county names (pun intended!). In particular, in how many US states the most common county name appears.
First find all the US states in the Entity framework:
In[]:=
states=EntityList[EntityClass["AdministrativeDivision","AllUSStatesPlusDC"]];
Find all the US counties:
In[]:=
counties=Map[EntityList[GeoEntities[#,"USCounty"]]&,states];
Group the counties that have the same common name:
In[]:=
groups=GroupBy[Flatten[counties],StringTrim[#[[2,1]],"County"]&];
Find the counties that appear in at least 25 states (that’s about one half of them!):
In[]:=
target=ReverseSortBy[Select[groups,(Length[#]>=25)&],Length];
How many?
In[]:=
Length[target]
Out[]=
5
What are the common names?
In[]:=
names=Keys[target]
Out[]=
{Washington,Jefferson,Lincoln,Jackson,Franklin}
Visualize the number of states per each county:
In[]:=
PieChart[Length/@Values[target],ChartLabels->names,LabelStyle->{14,Bold}]
Out[]=
These names correspond to the past US presidents:
In[]:=
presidents=Interpreter["Person"][names]
Out[]=

George Washington
,
Thomas Jefferson
,
Abraham Lincoln
,
Andrew Jackson
,
Benjamin Franklin

Find the years they were alive:
In[]:=
years=MapRowDateValue#
date of birth
,"Year"," - ",DateValue#
date of death
,"Year"&,presidents
Out[]=
{1732 - 1799,1743 - 1826,1809 - 1865,1767 - 1845,1706 - 1790}
Plot the counties on the map of the United States:
In[]:=
legend=SwatchLegend[ColorData[97,"ColorList"][[1;;Length[target]]],MapThread[Row[{#1," ",#3," (",Length[#2],")"}]&,{names,Values[target],years}]];
In[]:=
Legended[GeoGraphics[Table[{EdgeForm[ColorData[97,k]],ColorData[97,k],Polygon/@target[[k]]},{k,1,Length[target]}],GeoBackground->"VectorMonochrome",ImageSize->700,PlotLabel->"Five most popular county names in the U.S."],legend]

CITE THIS NOTEBOOK

Most popular county names in the U.S.​
by Gosia Konwerska​
Wolfram Community, STAFF PICKS, November 18, 2024
​https://community.wolfram.com/groups/-/m/t/3323292