Like every other kid in America, I was taught that Marconi invented radio. Nope.
After Tesla's death, his widow pursued his patent case all the way to the Supreme Court. They finally yanked Marconi's early patents for radio and gave them to Tesla for two reasons:
1. Tesla's were first.
2. Tesla's were right.
Marconi was, like Edison, a smart guy and a great showman, but also like Edison, not a scientific power. His basic theory of how radio worked was fundamentally, unforgivingly wrong. It's one of the reasons Fessenden and others beat him to voice transmissions - Marconi's theory "proved" they were impossible. He loved being famous - Mussolini was Best Man at his wedding - more than he strove to be right.
A great deal of information is available regarding Marconi's equipment. Based on that, several attempts have been made to reproduce his "first trans-Atlantic radio broadcast". All have failed, for reasons both technical and meteorological.
Marconi and Tesla knew each other. Tesla thought Marconi was an annoying clown. Marconi hated and feared Tesla, one of the few times he was right.