The United North American States (UNAS) is a coalition on Earth at the time of Mass Effect. It was created in the late 21st century when the nations of Canada, Mexico, and the United States of America merged together.
The Second American Civil War
Sometime around 2096 CE, Canada, Mexico, and the United States of America united to form the United North American States. This new union was strongly opposed by factions of secessionists, including the extremist group Freedoms First. On the morning of November 1, 2096, the New York chapter of Freedoms First attacked Liberty Island and destroyed the Statue of Liberty. Outrage at this brazen act triggered the Second American Civil War between the secessionists and UNAS forces.
Founding the Systems Alliance
In 2149 CE, following the discovery of a cache of Prothean technology on Mars, the United North American States and seventeen other nations ratified the Systems Alliance charter, establishing a representative political body to expand and defend human territory. The UNAS also contributed military assets to the Systems Alliance's fledgling military.
Dispute over Watson
The garden world of Watson was discovered in 2165 CE, with credit claimed by the Chinese People's Federation, the European Union, and the United North American States. This resulted in a political dispute over which coalition could settle Watson first. To resolve this, the Systems Alliance brokered the Reykjavik Compromise which allowed each coalition to establish its own settlements on the planet.
Assassination of President Aguilar
In 2176 CE, President Enrique Aguilar of the UNAS was assassinated during a photo opportunity with Chinese People's Federation premier Ying Xiong. The perpetrator was Michael Moser Lang, a patent clerk and political dissident from Virginia. Lang obtained a Kassa Fabrication M-12 Locust submachine gun and concealed it within a shoulder-mounted video camera which he brought to the event. The first burst from Lang's weapon broke through the kinetic barriers protecting the stage. Xiong attempted to shield Aguilar from the line of fire, but Lang's next shots passed completely through Xiong and killed both men.
Ford v. Huerta
During his term in office, President Christopher Huerta of the UNAS suffered a stroke that left him legally dead for 90 minutes before his brain functions were transferred to a computer. In 2185 CE, UNAS Speaker of the House Lisa Ford brought a case against Huerta arguing that his time in office after the stroke was illegitimate; if Huerta was considered dead, then according to the country's line of succession Ford would have been Vice President for the past year. The Systems Alliance agreed to hear the case of Ford v. Huerta, and ruled in a 5-4 decision that Huerta's term in office after his stroke was legitimate. This resulted in a wave of protests against the decision in several major UNAS cities.
The Reaper War
The UNAS was one of many Earth nations invaded by the Reapers in 2186 CE. Commander Shepard was present in the city of Vancouver as the first Reaper forces landed there, and escaped on the Normandy SR-2. Simultaneously, reporter Emily Wong witnessed the invasion at Los Angeles and transmitted her experience via a Quantum Entanglement Communicator, one of the few communication systems that continued to function after the Reapers destroyed the comm buoy networks, GPS and communications satellites, and undersea fiber-optic cables. The Reapers bombarded military bases, nuclear missile silos, industrial centers, and completely annihilated cities with populations in the low millions, including Fort Worth. Due to the communications blackout, no other details about the state of the UNAS during the Reaper occupation are known.
*Part of the Texan Megapolis
**Seattle and Vancouver are a single city