Geography and climate are among the most powerful forces that shape history, and you can certainly see their effects on the colonization of North America. Early colonists crossed the Atlantic, landing in unfamiliar terrain at great distances from their homes. What resulted was an often desperate (even harrowing) struggle for survival.
One thing to keep in mind is just how risky colonization actually was; there was never a guarantee that a colony would be successful, nor that the colonizers would survive. Indeed, even the first successful English colonies at Jamestown (founded in 1607) and Plymouth (1620) came dangerously close to collapse. In both cases, climate and environmental conditions contributed greatly to that near-failure.
Jamestown was built in a swamp for defensive purposes, but this led to disaster as the colony, overwhelmed with mosquitos, was immediately devastated by outbreaks of disease. While John Smith, because of a dominant personality, was able to provide some stability by forcing the settlers to work at cultivation for their own survival, the situation would deteriorate further in the winter of 1609, under the effects of a famine so severe that it even resulted in cases of cannibalism. This history illustrates just how severe and dangerous these conditions could be.
The Plymouth Colony, far to the north in New England, reveals another example as to the desperation that early colonization often tended to entail. Like Jamestown, the Plymouth colony came dangerously close to collapse, and like with Jamestown, environmental conditions were critical in shaping this near-disaster. The Pilgrims set up their colony amid poor soil and would be devastated by the outbreak of winter (one far more severe than the winters they'd experienced in England). Like in Jamestown, mortality rates were severe, and (as has been commemorated by the holiday of Thanksgiving), the Pilgrims only survived thanks to the assistance of the Native Americans.