Binecon wrote:
BillyBatson4360 wrote:
Did Jack sue Marvel at that time claiming ownership of the FF, Thor, Silver Surfer, Spider-Man, and others? No, he did not.

He knew that he did not own the characters he had a hand in creating. Just as he did not own the Boy Commandos, the Newsboy Legion, and countless others created under work for hire for other publishers.
While it's a somewhat sad situation, this post gets it right.
I wouldn't necessarily conclude that he knew he did not own the characters. Legal battles are costly -- both in coin of the realm and emotional toil -- and to pursue that course threatened Kirby's livelihood., which was drawing comics as a freelancer. To sue Marvel would certainly make it difficult to find work with that company, and might cause opportunities to dry up at other firms. (After all, who wants to hire a troublemaker? You saw how DC reacted when some of their long-time talent sought to form a guild for health benefits.) I think Kirby made a pragmatic decision. He was drawing a good page rate, he had plenty of work and it made little sense to risk all that to pursue legal action with all its uncertainties.