@EarlVanDorn
Yes, ignore the “after Katrina” reply, that is just wrong regarding its national makeup. It is true that there was a tremendous spike in applications after Katrina, but Tulane had already long had substantial Eastern corridor representation by then, along with strong Midwest pockets such as St. Louis and Chicago.
Tulane has a long and very interesting history, and obviously I am not going to cover it all here. But in short, Tulane began as a state school in 1834 as the Medical College of Louisiana. It then became the University of Louisiana, closed during the Civil War, reopened, but then shortly after became private when Paul Tulane, a wealthy businessman from New Jersey, was looking to donate millions. Obviously that is when the school was renamed as well. Side fact is he first offered his millions to Princeton but withdrew the offer when they wouldn’t rename that school. He did a lot of business in NOLA, Louisiana needed money post Civil War/Reconstruction, and the deal was done. Another interesting fact is that even today, as a result of that late 1800’s deal, every Louisiana state representative gets a scholarship to Tulane to give away, and Tulane gets certain tax breaks they otherwise would not on property and other assets that wouldn’t normally be covered under their not-for-profit status. Turns out the loss of tuition income and the tax savings pretty much offset each other. To this day Tulane is the only public college to become a private one.
Tulane was, of course, all male at that time. Around that same time Josephine Louise Newcomb, a wealthy widow and grieving mother over the death of her young Sophie (around 12 I think, without looking it up), began Sophie Newcomb College for Women, which became the first coordinate college for women when she joined with Tulane. It preceded the various partnerships of the Ivies such as Harvard/Radcliffe, Brown/Pembroke, and Columbia/Barnard. The only single sex dorm at Tulane is JL, named for the founder of the college. Newcomb College was merged fully into Tulane after Katrina, but it had long before stopped being separate in any significant fashion other than symbolically and emotionally. A court fight ensued over whether Tulane had violated the terms of the Newcomb donation, and Tulane won.
Now to get to your point, the other thing that is important to know is that New Orleans, being the ultimate melting pot of nationalities and cultures, was also very open in terms of religion. It was mostly Catholic but had its fair share of the various Protestant religions, African religions and their nearby island variations, and probably the second largest Jewish population after New York, at that time. This became very attractive to the Jewish populations of the East Coast, from Boston to Baltimore, as NOLA was known to be very accepting. Tulane was welcoming, and at that time the Ivies were not. Word spread about the school in general which, somewhat surprisingly, never gained a reputation as a “Jewish school”. Obviously it was still heavily Christian, even more so than today, so I suppose that is why. In any case, this led to a bit of a pathway, if you will, where Tulane was mostly southern kids but had a healthy representation from the Northeast-Midatlantic corridor, and not just the Jewish students as word spread of the quality of the school. Subsequently many of those families had members that moved west, especially to St. Louis and Chicago. Representation grew from there as well.
Naturally the advent of air travel helped a little, but the interstate highway system of the 50’s made a huge difference, as airfare was very expensive. Now the cheaper fares have made Tulane far more accessible, and not coincidentally West Coast representation has grown substantially since the 90’s. Excellent recruiting efforts there were key as well, and in general great word of mouth about Tulane.
I won’t claim every detail is exactly correct as I have not gone back like a historian to check against primary sources, but it is substantively the answer to your question. In summary, Tulane has had a national student representation for many decades, even preceding going private. But that is when it started to really start to get its national reputation and representation, and that has steadily increased even right through today as the West Coast area kicked in in a big way relatively recently. Now international is starting to increase, although still small as a percentage. Of course, most of what I refer to is about undergrads, not the grad and professional schools. I know little about the latter’s history and makeup.