The Smithsonian has a bit on Action Comics #1 and Captain America #1 and their recent acquisition of both:

“Taken together, the comics reflect societal anxieties and aspirations alike—whether in Superman’s immigrant origins or in Captain America’s wartime ethos. ‘The pivotal creators of these comics—Jerry Siegel, Joe Shuster, Joe Simon and Jack Kirby—were all first-generation Jewish Americans, anxious to make their marks in a country that had welcomed their parents,’ says Paul Levitz, president of DC Comics from 2002 to 2009 and writer of many comics, including Superman, via email. ‘As someone who had the pleasure of knowing them all, I can confidently say that this recognition of their work in the most significant comic book acquisition in decades, would have been a great affirmation of the groundbreaking genre that they created.’

The creators’ children echo those sentiments. Siegel’s daughter, Laura Siegel Larson, notes: ‘The museum already holds my dad’s portable typewriter. Now they have Action Comics No. 1, the holy grail of Superman artifacts.’ And Simon’s son Jim says, ‘It is wonderful to know that my father, Joe Simon, and Jack Kirby’s work is not only forever immortalized in the hearts of millions but also in the highest of institutions where it will be forever preserved.'”

Read more here.