American Generation Fast Facts

(CNN)Here's a look at six generations of Americans in the 20th century: the Greatest Generation (or GI Generation), the Silent Generation, baby boomers, Generation X, millennials and Generation Z. In order to examine economic trends and social changes over time, demographers compare groupings of people bracketed by birth year. There are sometimes variations in the birth year that begins or ends a generation, depending on the source. The groupings below are based on studies by the US Census, Pew Research and demographers Neil Howe and William Strauss.

The Greatest Generation (or GI Generation)
Born in 1924 or earlier.
Tom Brokaw coined the term the Greatest Generation as a tribute to Americans who lived through the Great Depression and then fought in WWII. His 1998 bestselling book, "The Greatest Generation," popularized the term.
    John F. Kennedy, born in 1917, was the first member of the Greatest Generation to become president. Lyndon B. Johnson,