There are no STATES that start with the letter "j", unless you count New Jersey. cities, well, most obviously Jacksonville. Lesser knowns include Jackman, ME, Jackpot, NV, Jacinto City, TX, etc...
Jacksonville
Joliet is a city in Illinois. It begins with the letter J.
There is one incorporated municipality in Wyoming that start with the letter 'J': Jackson. Other, Census Designated Population areas which start with 'J' are Jeffrey City, James Town, and Johnstown.
· Jerome is a town in Arizona
Jerome is a city in Idaho. It begins with the letter j.
Jirja is a city in Egypt. It begins with the letter J.
· Jirja is a city in Egypt
· Joondalup, Australia
Jane, MO
Jacksonville is a city in Florida. It begins with the letter J.
· Jefferson City, Missouri
Johnstown PA is one.