The four most celebrated holidays are listed in their own chapters.
For the rest of the year the events below are special to USA:
January: Dr. Martin Luther King, Jr. Holiday is marked around his birthday January 14th.
February: Valentines Day is celebrated February 14th with exchange of friendly cards among school children and run on the restaurants in the evening for the older crowd.
Also in February is Presidents Day commemorating the presidents Lincoln (born Feb. 12th) and Washington (birthday Feb. 22nd).
May: Memorial Day is celebrated as a national holiday on Friday before the last weekend in May.
September: Labor Day makes the first weekend in September a three day weekend. School has started, summer is officially over - even if September can be one of the warmer months of the year.
October: Columbus Day Oct. 12th is a controversial holidays that in places has changed name to Indigenous People's Day or Native Americans' Day or is not celebrated at all.
November: Veterans Day Nov. 11th is in other countries known as Armistice Day for the armistice of WWI. In USA it honors veterans of wars from WWI and later. There are parades in many places.
December: New Years Eve happens at various times across the continent as each time zone passes midnight. In New York a big ball is dropped on Times Square at midnight EST and this event is replayed on TV every hour until the whole country has entered the new year. As USA hasn't signed the international convention regarding location names of food products you can get American Champagne. The producers with parent companies in France call it Sparkling Wine - not champagne - but regardless of the name it can make for a festive New Year party. Happy New Year.