Why was it called that Brachiosaurus?

During the bone wars of the mid to late 1800s, paleontologists Cope and Marsh were competing to discover and name the most dinosaurs. As a result, Marsh discovered the already established Apatosaurus next to a new species Camarasaurus skull and named it the Brontosaurus or "Thunder Lizard". The scientific classification laws state that once a species is named in a published journal, that first name is the official name for the species. Therefore the Brontosaurus has been wiped out of the history books and it is once again the Apatosaurus.