- There are no firmly established sources for the union's origins. Star Trek: Shadowstar Station continuity mentions a South American Conflict and military engagements between the United States of America and Brazil -- all in the first half of the 21st century -- but with no details as to the precipitating events that led to those.
In the late 2120s, the South American Union and the Eastern Coalition joined the United Earth Republic rather than be overthrown by their own people. (Last Unicorn Games RPG: All Our Yesterdays: The Time Travel Sourcebook)
- It has never been established if this is the same regional alliance as the Union of South American Nations, founded in 2008. As of 2010, the Union had 12 member nation-states.