|Covid-19|January 18 – The third Pacific expedition of Capt. James Cook, with ships HMS Resolution and HMS Discovery, first view O'ahu then Kaua'i in the Hawaiian Islands, which he names the Sandwich Islands.
February 5 – South Carolina becomes the first state to ratify the Articles of Confederation.
February 6 – American Revolutionary War: In Paris the Treaty of Alliance and the Treaty of Amity and Commerce are signed by the United States and France, signaling official recognition of the new republic.
February 23 – American Revolutionary War: Friedrich Wilhelm von Steuben arrives at Valley Forge, Pennsylvania and begins to train the American troops.
May 30 – Benedict Arnold signs US oath of allegiance at Valley Forge.
June 24 – A total solar eclipse takes place across parts of USA from Texas to Virginia.
June 28 – American Revolutionary War – Battle of Monmouth: George Washington's Continental Army battles the British general Sir Henry Clinton's army to a draw near Monmouth, New Jersey.
July 3 – American Revolutionary War: the Wyoming Massacre takes place near Wilkes-Barre, Pennsylvania, ending in a terrible defeat of the local colonists.
July 4 – American Revolutionary War: George Rogers Clark takes Kaskaskia.
July 27 – American Revolution – First Battle of Ushant: British and French fleets fight to a standoff.
August 29 – American Revolutionary War: The Battle of Rhode Island takes place when the Continental Army attempts to retake Aquidneck Island from the British.
September – The Massachusetts Banishment Act, providing punishment for Loyalists, is passed.
September 17 – The Treaty of Fort Pitt is signed, the first formal treaty between the United States and a Native American tribe (the Lenape or Delaware).
September 19 – The Continental Congress passes the first budget of the United States.
November 11 – American Revolutionary War: the Cherry Valley massacre
November 26 – In the Hawaiian Islands, Capt. James Cook becomes the first European to land on Maui.
The first settlement is made in the area of what is now Louisville, Kentucky by 13 families under Colonel George Rogers Clark.
Phillips Academy,a prestigious secondary boarding school in the United States, is founded by Samuel Phillips Jr.
The term "thoroughbred" is first used in the United States in an advertisement in a Kentucky gazette to describe a New Jersey stallion called Pilgarlick.
American Revolutionary War (1775–1783)
January 6 – Thomas Lincoln, farmer and father of the President of the United States Abraham Lincoln (died 1851)
February 22 – Rembrandt Peale, artist and museum keeper (died 1860)
June 12 – Philip Livingston, merchant and statesman from New York City (born 1716)
1778 in the United States Wikipedia
Events from the year 1778 in the United States.