How many US state capitals names start with the same letter as their state name?

There are 4 US state capitals that have the same starting letter as their state name, they are:

Dover, Delaware

Honolulu, Hawaii

Indianapolis, Indiana

Oklahoma City, Oklahoma

Dover is the smallest of these 4, with about 26,000 residents as of the 2020 census.

Honolulu became the newest capital when Hawaii became a state in August of 1959.

Indianapolis is known as the racing capital of the world because it's host to three of the world's highest-attended single-day events: the Indy 500, the Brickyard 400 and the U.S. Grand Prix Formula One race.

Oklahoma City is home to the NCAA Softball World Series held every year in late May and early June.