Thomas Jefferson kept a list of them on his wall. So did Albert Einstein. Ralph Waldo Emerson fretted over whether Napoleon was a true one.
Heroes. With all the adulation that's been heaped on second-time astronaut John Glenn - not to mention all the hand wringing over whether there are any truly great men and women around these days - historians say it's worth noting that Americans have obsessed about heroes for centuries.
"There is this kind of hero panic that we're in at the moment," says Sean Wilentz, a professor and director of the American studies program at Princeton University in New Jersey. "But that's a perennial in American history. Each generation seems to go through it."
Jefferson's list of heroes included Francis Bacon and Isaac Newton. Einstein's included physicist James Clerk Maxwell and Mozart. And Emerson, after much wrestling, pronounced in a famous essay that Napoleon was most definitely not a hero (contrary to popular opinion) because he lacked character.
That much said, however, many historians and social observers argue that these are changing times for the American hero - thanks to huge shifts in society, ranging from the explosive immediacy of the Information Age to a post-1960s culture that glorifies the rights of the individual over commitment to a greater common good.
"We're starved for heroes," says Peter Gibbon a research associate at Harvard University who is writing a book with the working title, "Heroism: The Lost Vision of Greatness." Although American-style democracy has always tended to buck the notion that some people are greater than others, Gibbon argues that the nation "is unusually debunking and unadmiring at the end of the 20th century, more so than at any other time in our history."