garson's most famous work, "macbird!", a 1966 counterculture drama/political parody of "macbeth" is "one of the most controversial plays produced in the 1960s". it was originally intended for an anti-war teach-in at berkeley. the first edition, which was self-published on the same offset press as the "free speech movement newsletter", had sold over 200,000 copies by 1967 when the play opened in new york in a production starring stacy keach, william devane, cleavon little, and rue mcclanahan. while these then-unknown actors went on to become fixtures in american theater, movies and television, the author "disappeared from public view at the height of fame". the play has since seen over 300 productions worldwide and sold over half a million copies". macbird is remembered as an attack on then-u.s. president lyndon johnson. in fact, it presented johnson's predecessor, john kennedy, and his would-be successor robert kennedy as equally unacceptable but more dangerously alluring. garson wanted her fellow 1960s activists to step away from the democratic party and create their own institutions, including a third party. to that end, she could sometimes be seen outside of california theaters where macbird was playing, gathering signatures to put the peace and freedom party on the ballot. critical reaction was mixed and the play "has had advocates and detractors of equal stature." dwight macdonald, in "the new york review of books", called it "the funniest, toughest-minded most ingenious political satire i've read in years…" robert brustein wrote that "although this play is bound to start a storm of protest (not all of it unjustified) and may even be suppressed by some government agency, it will probably go down as one of the brutally provocative works in the american theater as well as one of the most grimly amusing," and praised garson as "an extraordinarily gifted parodist."