About the Time Our Timbers Were Seedlings:

1658 French traders Medard Chouart and Pierre Esprit Radisson became the first Europeans to make contact with the tribes of the Northern Plains when they ventured west and south of Lake Superior in search of furs. link
1660 The Navigation Act of 1660 stated that all colonial produce and tobacco must be exported on English vessels or colonial-owned ships with English captains. link
1660 Mary Dyer was hanged for preaching in Boston (the crime: Quakerism). link
1663 The Navigation Act of 1663 required that most imports to the colonies must be transported via England on English ships. link
1664 The Dutch New Netherland colony became English New York after governor Peter Stuyvesant surrendered to the British following a naval blockade. link
1664 Maryland Colony passed a law making lifelong servitude for black slaves mandatory to prevent them from taking advantage of legal precedents established in England which grant freedom under certain conditions, such as conversion to Christianity. Similar laws were later passed in the colonies of New York, New Jersey, the Carolinas and Virginia. link
1665 William Darby's "Ye Bare and Ye Cubb", reportedly the first English-language play presented in the colonies, was performed. link
1665 The Great (Bubonic) Plague devastated London. Smoking tobacco was thought to have a protective effect. link
1666 Isaac Newton explained his calculus. link
1666 Robert Boyle explained temperature-pressure-volume relations in gases. link
1666 Isaac Newton published his physical laws. link
1669 Rene de La Salle may have explored the Ohio River. link
1680 Native Americans of present day Montana acquired horses.  
1680 Native Americans of present day New Mexico revolted against Spanish domination. This is said to be the only successful revolt ever waged in the Americas against the Spanish presence. link
1682 Rene de La Salle navigated down the Mississippi River, naming the region Louisiana and claiming it for France. link
Vitus Bering conducted a number of expeditions to what is now the Bering Strait and the coast of Alaska. link
1774 Juan Perez commanded the first Spanish expedition to explore the Northwest Coast and sighted the Olympic Mountains. link