Simplify the following text for a Grade 7 native English-speaking person.
Original: Generally regarded to be the first thermoplastic , it was first created as Parkesine in 1862 and as Xylonite in 1869 , before being registered as Celluloid in 1870 .
Simplified: It was the first thermoplastic . It was first called Parkesine in 1856 , then Xylonite in 1869 and then Celluloid in 1870 .