Simplify the following text for a Grade 6 native English-speaking person.
Original: The norther half of WÃ 1\/4 rttemberg became the state of WÃ 1\/4 rttemberg-Baden under US-administration .
Simplified: After World War the Kingdom of WÃ 1\/4 rttemberg became the Free Peoples ' State of WÃ 1\/4 rttemberg .