The printing press helped and encourage the European exploration in the XV century in various ways.
The main consequence is that it was possible to spread the knowledge about this discovery quicker than in the past, making people aware of the progress made and giving to more people the benefits derived from explorations.
As the information travel across Europe and more people knew about the possible advantage of the new discoveries, more people wanted to start their own expeditions.
Moreover, the printing press made possible for explorers to share their difficulties, so they can help future explorations and explorers.
Ultimately, it was the power of the knowledge that the printing press made accessible to more people that powered the Europian exploration of the XV century.
"as a question of property rights" is the best option as to how slave labor in America was primarily seen in the 1850s, since it was an issue of state's rights.
