Simplify the following text for a Grade 4 native English-speaking person.
Original: Des Moines takes its name from Fort Des Moines ( 1843 â `` 46 ) , which was named for the Des Moines River .
Simplified: Des Moines was started in 1843 where the Raccoon River and Des Moines River meet . Des Moines became the capital of Iowa in 1857 .