Final answer:
Starvation and disease were the primary factors contributing to the high mortality rate of the Jamestown settlers during their first voyage.
Step-by-step explanation:
The high mortality rate of the Englishmen who made the first voyage to what would become Jamestown, Virginia was most significantly due to starvation and disease. The settlers faced a harrowing period known as “the starving time” during the winter of 1609-1610, where food shortages led to extreme hunger, and poor living conditions promoted the spread of diseases. Contributing factors included their lack of knowledge in agriculture resulting in their inability to grow their own food, internal political disputes, and conflicts with the Native Americans, such as the Powhatan tribe. Additionally, the expectation to find gold and generate profit for the Virginia Company led to a misallocation of effort which exacerbated their plight.