I want to preface this with a disclaimer: traditions change a lot depending where you are in the US just like other countries. For my family, we usually meet up with my extended family and have a BBQ on holidays when it's warm outside. On the 4th of July and 24th of July (Pioneer day which is pretty much only a holiday in Utah or for members of the Church of Jesus Christ of Latter Day Saints) we'll watch the huge fireworks they set off in the sky.
During Christmas we'll all meet up at my grandparents for Christmas dinner. For easter we'll do the same but the little kids will run around trying to find plastic eggs filled with candy that are hidden around the yard.