Simplify the following text for a Grade 5 native English-speaking person.
Original: Two years of renovation and new construction for an Indy-based road course led to the first United States Grand Prix there in 2000 , a race which was a great success .
Simplified: A new Indy-based road course using part of the oval track , and part of the infield was built in two years . The first United States Grand Prix held at the Speedway was in 2000 .