From wiki;
State laws
Each US state has its own age of consent. Currently state laws set the age of consent at 16, 17 or 18. The most common age is 16.[10]
age of consent 16: Alabama, Alaska, Arkansas, Connecticut, District of Columbia, Georgia, Hawaii, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Montana, Nevada, New Hampshire, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Vermont, Washington, West Virginia
age of consent 17: Colorado, Illinois, Louisiana, Missouri, Nebraska, New York, Texas
age of consent 18: Arizona, California, Delaware, Florida, Idaho, North Dakota, Oregon, Tennessee, Utah, Virginia, Wisconsin, Wyoming.
These state laws are discussed in detail below.
I was wrong, it's 12 states.
But still.
In every other G8 (the most developed countries in the world) country, the age of consent is 16 or less (with close in age exceptions.)
From what I've seen on this forum, most Americans think it is completely wrong that 17 year olds are having sex and also are misinformed that having sex with a 17 year old will end you in prison, when this is only reality in 12 of your 50 states.
Weird.