Simplify the following text for a Grade 12 native English-speaking person.
Original: Wills originally planned to dedicate this new cemetery on Wednesday , October 23 , and invited Edward Everett , who had served as Secretary of State , U.S. Senator , U.S. Representative , Governor of Massachusetts , president of Harvard University , and Vice Presidential candidate , to be the main speaker .
Simplified: He had also served as Secretary of State , U.S. Senator , U.S. Representative , Governor of Massachusetts , president of Harvard University , and Vice Presidential candidate .