The US's largest electoral states over time

Three states have been the largest electoral prize:

Virginia (1792-1808)
New York (1812-1968)
California (1972-)

Pennsylvania held the spot of the second-largest electoral prize from 1824 to 1948. California and Pennsylvania were tied from 1952 to 1960, and California was clear second from 1964 to 1968. From 1972 to 2000, it was New York, and from 2004 on, it has been Texas. Counting just the states that held the second spot for more than one decade (from 1824 on):

Pennsylvania (1824-1948)
...
New York (1972-2000)
Texas (2004-)

Ohio was the third-largest electoral prize from 1844 to 1888, and Illinois, from 1892 to 1948. From 1952 to 1960, because two states were tied for second, there was no third-largest electoral state. From 1964 to 1980, it was Pennsylvania; from 1984 to 2000, Texas; from 2004 to 2008, New York. From 2012 to 2020, New York and Florida were tied for third, and from 2024 on, Florida will be in clear third:

Ohio (1844-1888)
Illinois (1892-1948)
...
Pennsylvania (1964-1980)
Texas (1984-2000)
New York (2004-2008)
...
Florida (2024-)

Ohio was the fourth-largest electoral prize from 1824 until 1840 (behind Virginia); then Virginia was #4 from 1844 to 1860. In 1864, Illinois took the fourth spot (keeping it after Virginia's readmission), and held it until 1888. Ohio was demoted to #4 in 1892 and held the spot until 1940. In 1944 and 1948, Ohio and California were tied for #4. From 1952 to 1968, Illinois held clear fourth, and was tied with Texas for fourth from 1972 to 1980. Pennsylvania was fourth from 1984 to 1988, and Florida, from 1992 to 2008. From 2012 to 2020, because two states were tied for third, there was no fourth-place state. From 2024 on, it will be New York.

Ohio (1824-1840)
Virginia (1844-1860)
Illinois (1864-1888)
Ohio (1892-1940)
...
Illinois (1952-1968)
...
Pennsylvania (1984-1988)
Florida (1992-2008)
...
New York (2024-)

---

2004 was the first time in US history that the first- and second-largest electoral prizes were both non-original states (not amongst the original 13 colonies). 2024 will be the first time in US history that the first-, second-, and third-largest electoral prizes will all be non-original states. The arrangement of #1 California-#2 Texas also looks likely to be fairly stable, as does the arrangement of #1 California-#2 Texas-#3 Florida. Previous stable arrangements of the top two and top three have been:

1824-1948: #1 New York-#2 Pennsylvania
1972-2000: #1 California-#2 New York
2004-: #1 California-#2 Texas

1824-1840: #1 New York-#2 Pennsylvania-#3 Virginia
1844-1888: #1 New York-#2 Pennsylvania-#3 Ohio
1892-1948: #1 New York-#2 Pennsylvania-#3 Illinois
1984-2000: #1 California-#2 New York-#3 Texas
2024-: #1 California-#2 Texas-#3 Florida

The reason the arrangements beginning in 2024 seem likely to be stable is that none of the three states is now a state that was in the process of being displaced downward. Furthermore, there is a fairly wide spacing between California and Texas, and between Texas and Florida. California did lose an electoral vote in the 2020 census, but for one thing, this decision was somewhat questionable and doesn't seem likely to translate into a sustained electoral decline. (Back in 2015, Geoffrey Skelley wrote that California was trending towards adding one electoral vote.) For another thing, Texas gained 'only' two seats (it had earlier been projected to gain three), and the gap between California and Texas remains a sizeable 14. 

Ironically, it seems likely that New York will have a sustained period at #4 as well. The longest period the top four states all stayed the same was 1892-1940, when it was #1 New York-#2 Pennsylvania-#3 Illinois-#4 Ohio. I don't know if the foursome of #1 California-#2 Texas-#3 Florida-#4 New York will last that long. But New York now has a 9-EV lead over the next-largest states, which are Pennsylvania and Illinois, each at 19. Furthermore, both Pennsylvania and Illinois are also in decline. The largest growing states below New York are Georgia and North Carolina, which each now has 16 electoral votes, a full 13 below New York. 

But this simply bears out the special standing of California, Texas, and Florida as the uniquely large magnets within the broader Sun Belt. In 1990, David Broder wrote,

In terms of national political power, the biggest stakes are in California, Texas and Florida, the Sun Belt trio slated to gain more than a dozen additional House seats and electoral votes when this year's Census is complete.

And California and Florida in particular used to embody, as states, qualities associated with the Sun Belt more broadly:

Once upon a time, Florida and California were known as Dream States. Both have sunny skies, warm weather, long waterfronts, and additional natural qualities that affirmed cultural notions of paradise...[From 1869 to 1929] California and Florida unabashedly promoted themselves to tourists and investors as the American semi-tropics...

Even though this is describing a period before the Sun Belt phenomenon came into being, a journalist more recently (in 2011) wrote an essay echoing this view of California and Florida (the original appears to have been deleted, but sections have been preserved in a forum):

A lot of people drifted south to Florida to reinvent themselves. It's an odd juxtaposition of people that makes it so interesting

These new residents helped turn Florida into a destination with a cutting-edge art scene, an international music scene, posh neighborhoods, top-flight resorts and world-class amusement parks, among other attractions.

-- much of the state's strangeness comes from the fact that so many of its residents are dreamers. ... It's a 'dream state,'" he said. "It combines the American dream for immigrants with the dream of the promise of a better life or a second chance. ... Florida is so odd because it's a place people go to escape their pasts and pursue their fantasies -- weird as they may be.

Only California and Florida are legitimate 'dream states,'" Mormino said. "You have the sand dunes, the palm trees, and the promise of a better life ... or at least a better February.

And it's a pretty safe bet that whenever one hears about Mark Twain's comment about the four unique cities in the United States, it's coming from a San Antonio booster. If anything, the most organically enchanting 'city' (albeit no longer a very large one) between New Orleans and California is arguably the 'exotic city of Santa Fe', in New Mexico. An abstract for Henry Knight's Tropic of Hopes (which treats California and Florida) notes the two states' 'distinctive cities'.

(Noteworthily, Texas' growth was much more sluggish in the early postwar period, as can be seen in a comparison of how many EVs the states picked up each decade:

1944-1948
California: 25
Texas: 23
Florida: 8

1952-1960
California: 32 [+8]
Texas: 24 [+1]
Florida: 10 [+2]

1964-1968
California: 40 [+8]
Texas: 25 [+1]
Florida: 14 [+4]

1972-1980
California: 45 [+5]
Texas: 26 [+1]
Florida: 17 [+3]

It was only after 1980 that Texas added more than one seat, for the first time since 1930. In 1987, Bill Schneider picked two locations, one in California and one in Florida, as particularly emblematic of the Sun Belt [or isolated two locations that Nixon had chosen as emblematic of the Sun Belt]: 'By 1972 Nixon had become the candidate of the Sun Belt, of San Clemente and Key Biscayne.' Funnily enough, three of the original four big 'bowl games' were in California [Rose Bowl], Texas [Cotton Bowl], and Florida [Orange Bowl]. By the time it was replaced by the Fiesta Bowl as one of the big four bowls [in 1995], Texas had already begun matching California's and Florida's phenomenal growth rates, having added three electoral votes two censuses in a row.)