The smallpox blankets are unsubstantiated Ward Churchill BS. Smallpox vaccination, a procedure developed by the English country doctor Edward Jenner in 1796, was first ordered in 1801 by President Jefferson; the program continued in force for three decades, though its implementation was slowed both by the resistance of the Indians, who suspected a trick, and by lack of interest on the part of some officials.
http://hnn.us/articles/7302.html
Not necessarily smallpox it could of been just the flue we about wiped out the Hawaiians with the flue. Any sickness that came from Europe would be devastation on a civilization that did not have an immunity to it.