The National Museum of American History Is Displaying 250 Objects to Commemorate the Country’s Big Birthday. Here’s the Story Behind Ten of the Artifacts Featuring iconic and everyday items, including a Revolutionary War gunboat and a first-generation iPod, “In Pursuit of Life, Liberty & Happiness” is open now at the museum Visitors view the Star-Spangled Banner at the National Museum of American History National Museum of American History For more than three years, staff members at the Smithsonian’s National Museum of American History have been carefully planning a showcase of 250 objects across 250,000 square feet and all three floors of the building. The culmination of this work is finally here: “In Pursuit of Life, Liberty & Happiness” is open through the end of the year at the museum to mark the 250th anniversary of the Declaration of Independence. The museum aimed to represent the broadest possible sweep of American history.…