what are some areas that vote for the same party as they did decades ago

[𝕭𝖆𝖕𝖙𝖎𝖘𝖙𝖆 𝕸𝖎𝖓𝖔𝖑𝖆]

Gasconade County, Missouri has the longest ininterrupted streak of voting Republican, starting in 1860.
I am not sure how different the motivations of Missouri Rheinland voters in the late 19th century are from those of their descendants in the early 21st century, though.

[𝕭𝖆𝖕𝖙𝖎𝖘𝖙𝖆 𝕸𝖎𝖓𝖔𝖑𝖆]

Boston and Manhattan have pretty much always been Democratic; initially because of Catholic and Jewish immigration, now because virtually all major cities do.

By the same token Atlanta: first because of White Southerners, then because of Black voters, and nowadays it's clear that people of every race in Atlanta are strongly Democratic.
Atlanta was incorporated in 1847 and as far as I was able to collect it seems to have had weird voting patterns in the first years, but has clearly voted consistently Democratic from 1876 to now (with the possible exception of 1972, I am not sure about that).

[𝕭𝖆𝖕𝖙𝖎𝖘𝖙𝖆 𝕸𝖎𝖓𝖔𝖑𝖆]

Boston and Manhattan have pretty much always been Democratic; initially because of Catholic and Jewish immigration, now because virtually all major cities do.

By the same token Atlanta: first because of White Southerners, then because of Black voters, and nowadays it's clear that people of every race in Atlanta are strongly Democratic.
Atlanta was incorporated in 1847 and as far as I was able to collect it seems to have had weird voting patterns in the first years, but has clearly voted consistently Democratic from 1876 to now (with the possible exception of 1972, I am not sure about that).

Actually, I believe that according to the map of white vote by county that is somewhere on this forum, Fulton County whites narrowly preferred Trump in 2016, but you are nonethless right about Atlanta as a whole always having been Democratic.

Right, but that margin comes from the former-Milton-county part of Fulton County.
Atlanta Whites are sure as hell pretty Democratic.

[𝕭𝖆𝖕𝖙𝖎𝖘𝖙𝖆 𝕸𝖎𝖓𝖔𝖑𝖆]

I am surprised this has not come out yet, but the Rio Grande border counties in Texas are actually a pretty good response.

In particular, Starr County, TX is now the new recordholder for longest Democratic streak (not Republican since 1892). And unlike in the cases of say, majority black Southern counties, in this case the Dem base has not changed.

And same applies for most of the general area. Even in R landslides this area voted titanium D with the same kind of people voting D.

I mean, the point of this thread is areas that vote the same party bur for different reasons, so this answer, while correct, it's a bit "swing and a miss".