The historical connection
A 2016 International Action Center announcement names its Boston group and uses the iacboston.org email domain. This is a primary source for the organisation’s account of that event, rather than independent verification of every claim in the announcement.
Keep the event in its time
Record the publication date separately from the event date. An old call to gather is part of a historical record; it is not a current invitation. This independent archive does not organise events, solicit donations or speak for the group.
Read across sources
Compare the announcement with contemporaneous reporting and other records. Note agreement and disagreement explicitly. Avoid blending an organisation’s viewpoint into the voice of a neutral chronology.