Answer:
The Spanish and Portuguese were able to lay effective claims to American empires in the 1500s due to several factors. These included advanced technology, military superiority, and the lack of centralized power among the indigenous peoples of the Americas. Additionally, the Europeans brought with them diseases that devastated native populations, making it easier for them to conquer and control these societies. The Spanish and Portuguese also established long-term colonies and trading networks that helped solidify their hold on the region.