Counties with the longest streak of voting for one party for President

[GMantis]

Based on this list and this series of maps, some additions to Nym's list (not including those counties already mentioned by other users):

Kentucky

R: Clay, Owsley (Since 1860, though both of these counties were substantially bigger at the time

Texas

D: Brooks (Since 1908, ie every time since the county was founded in 1911)

West Virginia:

R: Morgan (Since 1860)

[GMantis]

Thank you for this!

Illinois

D: Cook, St. Clair (since 1972)
R: Edwards, Lee, Ogle (I in 1912, never D in the history of the Atlas which goes back to 1892)

Interesting, Edwards County last voted D in 1832, Lee County in 1852.  Ogle County has never once voted for a Democrat for President.  geoelections.free.fr/USA/elec_comtes/1852.htm

All 3 counties voted for Teddy Roosevelt in 1912 like you mentioned, but otherwise have all voted Republican since 1856.  Even though they are 300 miles apart!

What's interesting about Edwards county is that it's in southern Illinois, for a long time a Democratic stronghold, so it is starkly contrasted with the Democratic counties surrounding it on many election maps.

[GMantis]

Thank you for this!

Illinois

D: Cook, St. Clair (since 1972)
R: Edwards, Lee, Ogle (I in 1912, never D in the history of the Atlas which goes back to 1892)

Interesting, Edwards County last voted D in 1832, Lee County in 1852.  Ogle County has never once voted for a Democrat for President.  geoelections.free.fr/USA/elec_comtes/1852.htm

All 3 counties voted for Teddy Roosevelt in 1912 like you mentioned, but otherwise have all voted Republican since 1856.  Even though they are 300 miles apart!

What's interesting about Edwards county is that it's in southern Illinois, for a long time a Democratic stronghold, so it is starkly contrasted with the Democratic counties surrounding it on many election maps.

I really don't know much about this, but I remember reading that - while Democrats certainly held most of the power in Southern Illinois - it depended on the geography.  Contrary to popular belief, the southern third of Illinois is pretty different from Northern and Central Illinois, and it isn't just a bunch of cornfields.  There were coal mines there, several areas of swampland and the Shawnee National Forest; it's actually quite beautiful.  Anyway, I remember reading one time that the areas with good farming tended to be more Republican in the traditionally conservative Midwestern mold and the areas with less corn tended to be more Southernized and Democratic ... not sure how I could back that up, though, too lazy to look at the maps.

Well, if we're discussing maps, I was thinking of this map (or any map up to and including 1892 for that matter) where Edwards county is entirely surrounded by Democratic counties. It seems that while there were always Republican areas in southern Illinois, the southeast was particularly strongly democratic, except for Edwards.

[GMantis]

Interesting how there are far fewer Dem streaks than Rep streaks as the latter has many rural counties outside the South. Here are the longest Dem streaks:

Brooks, TX (Since 1908, i.e. every time since the county was founded in 1911)

Northampton, NC (Never R in Atlas history which dates to 1924)

Costilla, CO; Suffolk, MA; Ramsey, MN; St. Louis City, MO; Deer Lodge, MT; Bronx, NY; Kings, NY; New York, NY (since 1924)

Duval, TX, Jim Hogg, TX, Maverick, TX, Starr, TX, Webb, TX, Zapata, TX (never R in consecutive Atlas history which dates to 1940, though Webb and Zapata voted R in 1912)

All are Northern urban or majority-minority except for Deer Lodge, MT.

Starr started its streak in 1896 (currently the longest Democratic streak), Northampton in 1900, Duval in 1904, Webb and Jim Hogg in 1916 (the latter was only founded in 1913) and Zapata in 1924. Here is the full list and you can also check the maps for each year.