www.marathonguide.com is a good site if you want to get a listing of marathons in the US as well as as international. Apparently, it's been around for a long time, longer than the Internet itself. Check out this listing below - you can still run a marathon in Yugoslavia - a country that hasn't existed for a few years now.
But, below is the proof that marathonguide.com is older than the Internet. Check out Mumbai as shown by the black arrow in the screen capture below. It is listed as "British Indian Ocean Territory." Given that India gained independence in 1947 and that the Internet didn't exist back then, there is only one logical conclusion you can draw.
However, strangely enough, Bangalore is listed under "India".