 During the winter , the Mayflower colonists suffered greatly from lack of shelter , diseases such as scurvy , and general conditions onboard ship . Many of the able @-@ bodied men were too infirm to work ; 45 out of 102 immigrants died and were buried on Cole 's Hill . Thus , only seven residences ( of a planned nineteen ) and four common houses were constructed during the first winter . By the end of January , enough of the settlement had been built to begin unloading provisions from the Mayflower . In mid @-@ February , after several tense encounters with local Native Americans , the male residents of the settlement organized themselves into military orders ; Myles Standish was designated as the commanding officer . By the end of the month , five cannons had been defensively positioned on Fort Hill . John Carver was elected governor to replace Governor Martin . 
