Simplify the following text for a Grade 6 native English-speaking person.
Original: While Hitler was in prison , RÃ hm helped to create the Frontbann as a legal alternative to the then-outlawed SA .
Simplified: In 1924 , RÃ hm helped start the Frontbann , an alternative to the Sturmabteilung . After an argument with Adolf Hitler , RÃ hm retired as leader of the SA .