History of North America--North America

Further information: Canada in the World Wars and Interwar Years, Mexican Revolution, and History of the United States (1918–1945)
 
A Canadian World War I recruiting poster - (1914–1918)As a part of the British Empire Canada immediately entered World War I. Canada bore the brunt of several major battles during the early stages of the war including the use of poison gas attacks at Ypres. Losses became grave, and the government eventually brought in conscription, despite the fact this was against the wishes of the majority of French Canadians. In the ensuing Conscription Crisis of 1917, riots broke out on the streets of Montreal. In neighboring Newfoundland, the new dominion suffered a devastating loss on July 1, 1916, the First day on the Somme.

The United States stayed apart from the conflict until 1917, joining the Entente powers. The United States was then able to play a crucial role at the Paris Peace Conference of 1919 that shaped interwar Europe. Mexico was not part of the war as the country was embroiled in the Mexican Revolution at the time.

Further information: Roaring Twenties, Great Depression, and Cristero War
The 1920s brought an age of great prosperity in the United States, and to a lesser degree Canada. But the Wall Street Crash of 1929 combined with drought ushered in a period of economic hardship in the United States and Canada. From 1936 to 1949, this was a popular uprising against the anti-Catholic Mexican government of the time, set off specifically by the anti-clerical provisions of the Mexican Constitution of 1917.

Further information: Military history of Canada during the Second World War, Military history of the United States during World War II, United States home front during World War II, Potrero del Llano, Faja de Oro, and Escuadrón 201
Once again, Canada found herself at war before her neighbours, however even Canadian contributions were slight before the Japanese attack on Pearl Harbor. The entry of the United States into the war helped to tip the balance in favour of the allies. Two Mexican tankers, transporting oil to the United States, were attacked and sunk by the Germans in the Gulf of Mexico waters, in 1942. The incident happened in spite of Mexico's neutrality at that time. This led Mexico to declare war to the Axis nations and entered the conflict. The destruction of Europe wrought by the war vaulted all North American countries to more important roles in world affairs. The United States especially emerged as a "superpower".

Further information: History of the United States (1945–1964), History of Canada (1945–1960), and African-American Civil Rights Movement (1955–1968)
The early Cold War era saw the United States as the most powerful nation in a Western coalition of which Mexico and Canada were also a part. In Canada Quebec was transformed by the Quiet Revolution and the emergence of Quebec nationalism. Mexico experienced an era of huge economic growth after World War II, a heavy industrialization process and a growth of its middle class, a period known in Mexican history as the "El Milagro Mexicano" (Mexican miracle). The Caribbean saw the beginnings of decolonization, while on the largest island the Cuban Revolution introduced Cold War rivalries into Latin America.

Further information: History of the United States (1964–1980) and History of Canada (1960–1981)
The Civil Rights Movement ended Jim Crow and empowered black voters in the 1960s, which allowed blacks to move into high government offices. However, the dominant New Deal coalition collapsed in the mid 1960s in disputes over race and the Vietnam War, and the conservative movement began its rise to power, as the once dominant liberalism weakened and collapsed.. Canada during this era was dominated by the leadership of Pierre Elliot Trudeau. Eventually in 1982 at the end of his tenure, Canada received a new constitution.

Further information: History of the United States (1980–1991) and History of Canada (1982–1992)
Canada's Brian Mulroney not only ran on a similar platform but also favored closer trade ties with the United States. This led to the Canada-United States Free Trade Agreement in January 1989. Mexican presidents Miguel de la Madrid, in the early 1980s and Carlos Salinas de Gortari in the late 1980s, started implementing liberal economic strategies that were seen as a good move. However, Mexico experienced a strong economic recession in 1982 and the Mexican peso suffered a devaluation. In the United States president Ronald Reagan attempted to move the United States back towards a hard anti-communist line in foreign affairs, in what his supporters saw as an attempt to assert moral leadership (compared to the Soviet Union) in the world community. Domestically, Reagan attempted to bring in a package of privatization and regulation to stimulate the economy.

Further information: History of the United States (1991–present) and History of Canada (1992-Present)
The end of the Cold War and the beginning of the era of sustained economic expansion coincided during the 1990s. On January 1, 1994, Canada, Mexico and the United States signed the North American Free Trade Agreement, creating the world's largest free trade area. In 2000, Vicente Fox became the first non-PRI candidate to win the Mexican presidency in over 70 years. The optimism of the 1990s was shattered by the 9/11 attacks of 2001 on the United States, which prompted military intervention in Afghanistan, which also involved Canada. Canada did not support the United States' later move to invade Iraq, however.

In the U.S. the Reagan Era of conservative national policies, deregulation and tax cuts took control with the election of Ronald Reagan in 1980. By 2010, political scientists were debating whether the election of Barack Obama in 2008 represented an end of the Reagan Era, or was only a reaction against the bubble economy of the 2000s (decade), which burst in 2008 and became the Late-2000s recession with prolonged unemployment.