Cultural/phyletic/memetic complex that developed from the old USA and ex-USA polities and nation states and their cis-lunar and interplanetary colonies.
Americanism was characterized by a high-tech innovative attitude, a rugged individualism and mostly pro-capitalist attitude, a love of fads, pop-culture, and social exhibitionism (as characterized by the so-called "daytime" 2Ds and 3Ds in which guests would abuse each other and bare all in front of an international audience), a strong corporate culture and use of English language (the prototype of Anglic).
Even after the decline and fall of the original USA polity they retained great pride in their way of life. Americanism was influential in the establishment and development of a number of important early interstellar colonies, including Nova Terra (Tau Ceti II), Atlantis (Zeta Reticuli), Pacifica and at least a dozen colonies and polities called New America, New California, New Cascadia, etc. Although Americanism was perhaps one of the most important cultural complexes of the early Interplanetary Age, it was gradually supplanted by the superbright orbital and Jovian League cultures. Americanism remained entrenched in a number of Belt, Lunar, and Martian colonies - including those that survived the nanoswarms - right up until the early Federation period.