The United Canadian and American States is a fictional North American country in the
Shadowrun roleplaying game setting.
Seattle (the best documented area in the Shadowrun universe) is a
city-state within the UCAS.
The UCAS was formed October 13, 2030 when US President Andrew MacAlister and Canadian Prime Minister Harold Frazier signed a treaty to merge what remained of the USA and Canada. Both nations were smaller after losing much of their land to the Native American Nations in the 2018 Treaty of Denver. This weakening continued in 2029 when a powerful computer virus nearly destroyed the world's economy.
The creation of the UCAS went smoothly despite protests on both sides. By 2062 the UCAS had 31 states and a population of 131 million metahumans.
Sources:
Dumpshock Timeline Explorer (http://timeline.dumpshock.com/)
Shadowrun 3rd Edition
Shadows of North America
Sixth World Wiki (http://wiki.dumpshock.com/index.php/UCAS).