Simplify the following text for a Grade 6 native English-speaking person.
Original: Not only the first European to visit the island , but he was forced to spend the winter at what is now called `` Winter Harbour '' , until August 1 , 1820 owing to freeze-up of the sea .
Simplified: Not only did he find the island , but he had to spend the winter at what is now called `` Winter Harbour '' , until August 1 , 1820 .