States by Fraction of the US Population

d.w.rowlands [at] gmail.com

While it's well-known to modern Americans which states have relatively larger or smaller populations. However, the relative sizes of states have changed a lot over the past two centuries, both because of changes in population density and because of the addition of new states beyond the original thirteen. These changes, furthermore, are still happening. For example, New York lost two electoral votes in the 2010 census, and Florida gained two electoral votes, which means that they're now tied for third-most electoral votes, after California and Texas. Furthermore, given current population trends, Florida seems likely to overtake New York in the next census. The continued slide of New York behind sunbelt states is notable given that, starting with the 1810 census, New York had had the most electoral votes of any state for about a century and a half.

Adding to my interest on the matter, I recently read a book called Dred Scott and the Problem of Constitutional Evil, by Mark A. Graber that discussed at length the fact that the Framers nearly universally expected that the South would quickly greatly surpass the North in population, because they felt the Northern colonies were "full", while the Southern ones had large amounts of empty land, and they believed that the Northwest Territory (the modern states of Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota) was largely not worth cultivating, while the lands south of the Ohio would attract a large population. It turned out that they were wrong, especially since European immigrants flooded into the country and almost entirely preferred to settle in free, Northern states, which upset Constitutional provisions intended to protect a Northern minority.

It turns out that Wikipedia actually has an article with data on the historical population of states, which I was able to turn into a plot of state populations as a function of national population over time. Some clarifications about the data:

Plot of US states by the fraction of the national population that they contained in each census. Note that all values are shown for current state boundaries, not for the boundaries that the states (or territories) had at the time.
Plot of US states by the fraction of the national population that they contained in each census. Note that all values are shown for current state boundaries, not for the boundaries that the states (or territories) had at the time.

Some observations that struck me as interesting: