Final answer:
The Spanish conquistadors' arrival and settlement in Florida marked the start of significant European colonization in North America, leading to cultural exchanges, conflict, the spread of diseases, and tensions with other European powers.
Step-by-step explanation:
The arrival of the Spanish conquistadors in Florida and their establishment of the first settlement in North America had significant effects. As they settled, they clashed with indigenous groups, spread European diseases which were devastating to the native population, and initiated a period of colonization and mission-based conversion attempts. The Spanish Florida settlements also created tension between Spain and other European powers due to attacks by and on the English and French privateers using Florida as a base.
The establishment of settlements like St. Augustine by Pedro Menéndez de Avilés in 1565 marked the beginning of a continuous European presence on the North American continent, with St. Augustine becoming the oldest continuously-settled European city in the United States. This new foothold led the Spanish to push further into the Americas, instigating cultural exchange, conflict, and cooperation. The complex interplay between European explorers, indigenous populations, and enslaved peoples during this period laid the groundwork for the multicultural landscapes of modern North America.