Simplify the following text for a Grade 6 native English-speaking person.
Original: At this time the township developed and the Post Office opened on September 4 , 1863 ( closed in 1971 , though offices at Greta West and Greta South remained open until 1994 ) .
Simplified: At this time the township started with the Post Office opened on September 4 , 1863 . It closed in 1971 , though post offices at Greta West and Greta South remained open until 1994 .