Simplify the following text for a Grade 11 native English-speaking person.
Original: The Allgemeiner Deutscher Arbeiterverein continued after his death , however , going on to help establish the Social Democratic Party of Germany ( SPD ) in 1875 .
Simplified: Lassalle founded the Allgemeiner Deutscher Arbeiterverein ( General German Workers ' Association , ADAV ) in 1863 . This party later became the Social Democratic Party of Germany ( SPD ) .