The 2001 Congress of the Greens/Green Party USA, held at Carbondale, Illinois, was a critical event in the history of the Green Party in the United States. At the Congress, occurring July 20 to July 23, at which the G/GPUSA was to consider the Boston Proposal, a tentative "merger" agreement between it and the Association of State Green Parties (ASGP). After an intense internal organizational struggle, most of which revolved around whether or not to "accredit" various delegations (and thus grant the individuals within them voting privileges), the proposal was rejected; although 55% of the members in attendance voted to approve it (99 in favor, 81 against), the organization's bylaws required yes votes from a "super-majority" of 66.7% of the delegates in attendance to pass.
This result was very controversial, as many Carbondale participants who supported the Boston Proposal felt that a portion of the national G/GPUSA leadership who opposed it had illegitimately manipulated the accreditation process to reduce the level of support for the proposal and thus ensure it's failure. This (and other subsequent events) ultimately led to the exodus of a large number of G/GPUSA activists, many of whom later went on to found  and/or participate in The Green Alliance (an organization intended to bring "movement" politics in the style of the G/GPUSA into the Green Party of the United States, which they felt was overly focused on "electoral" politics, and relatively conservative).