How many U.S. states begin with the letter 'O'?

A U.S. state is one of the states of the United States of America. Four states (Kentucky, Massachusetts, Pennsylvania, and Virginia) are officially named a "Commonwealth" rather than a "State." Delaware is sometimes called the 'First State' because it was the first colony to accept the new constitution in 1787. The most recent state is Hawaii which became the 50th state on August the twenty-first, 1959.

There are three U.S. states that begin with the letter 'O', they are:

Ohio with its capital being Columbus and became a U.S state in March 1, 1803.

Oklahoma with its capital being Oklahoma City and became a U.S. state in November 16, 1907.

Oregon with its capital being Salem and became a U.S. state in February 14, 1859.