Final answer:
Samuel de Champlain believed that the St. Lawrence River was important because it provided easy access to France, served as a means of transportation, and was crucial for establishing a French empire in the New World.
Step-by-step explanation:
Samuel de Champlain believed that the St. Lawrence River was important for several reasons. First, it provided easy access to France, allowing for the transportation of people, goods, and information between the two locations. Second, the river served as a crucial means of transportation, facilitating exploration and trade within the continent. Finally, Champlain saw the St. Lawrence River as an essential route to establish a French empire in the New World, leading to further exploration and colonization in areas such as the Great Lakes and Mississippi River.