Miss America and Miss USA/Universe are totally different pageant systems and a lot of people don't realize that.
Miss America is a scholarship program and Miss USA is a beauty pageant.
The difference here is that Miss America is judged on many different aspects including interviews and Miss USA is a modeling based system. Though Miss USA does have an interview phase, the other phases, however, are of higher significance.
Miss USA leads to a larger pageant but Miss America doesn't.
Whoever wins the Miss USA pageant will go into preparation and compete in the Miss Universe pageant. Miss USA has won the Miss Universe title 8 times. Miss America is the highest title in that system. There is no pageant that comes after.
THE CROWN!
The crowns are very different but both are incredibly stunning. They're covered in sparkling stones, and if the crown alone doesn't convince you to compete, I don't know what will!
When it all began.
Miss America has been around longer. Miss America was started in the 1920's and Miss USA in the 1950's. Even though there is a large gap between years, they're both extremely popular. Each ranking in tons of views every year when the pageants are aired.
The talent phase.
Miss America has a talent phase in their competition. Each contestant is required to perform an artistic expression of their choice in the time range of 60-90 seconds. Talents range everywhere from singing, to dancing, to changing car oil on stage. (Psstt... You can watch some of these on YouTube). Miss USA however, does not have a talent phase.
The prize.
Miss USA receives many prizes, the biggest is her entry to the Miss Universe pageant. Miss America wins scholarship money normally ranging around $50,000.
Those are the major key differences between Miss USA and Miss America.