North America.

• Position: 2014 America's Challenges - Statistical data

Immigration

In the U.S., the debate continues over immigration reform and how to handle the 12 million undocumented immigrants already here. While illegal immigration from Mexico has slowed, poverty and drug violence in Central America and Mexico continue to fuel illegal crossings into the U.S., which plans to invest $40 billion in the next 10 years to tighten security along the border.

By the Numbers

25%

Percentage of undocumented immigrants in the U.S. who live in California, the state with the highest concentration

SOURCE: U.S. DEPARTMENT OF HOMELAND SECURITY

Mexico

Though poverty is still widespread, Mexico's booming economy has slowed emigration, attracted foreign investment, and lifted millions into the middle class. President Enrique Pena Nieto (above) has promised to scale back the government's war against drug cartels, which has killed more than 60,000 Mexicans since 2006. Most of the illicit drugs go to the U.S.

Canada

Canada is the largest supplier of oil to the United States. The boom in Canadian oil production from tar sands--a mix of clay, sand, water, and oil-has led to a fight over the construction of a new pipeline to transport the oil to the U.S. Environmentalists are concerned about possible oil spills and the release of greenhouse gases like carbon dioxide.

By the Numbers

1.9 million Barrels of oil imported daily by the U.S. from Canada

SOURCE: U.S. ENERGY INFORMATION ADMINISTRATION

Cuba

Since 2008, President Rail Castro has allowed limited free-market reforms to help revive Cuba's sagging economy. The Communist government now allows some Cubans to start their own businesses and to travel abroad with fewer restrictions. The U.S. trade embargo imposed in 1960 after the revolution remains in effect.

Sources

For area, population, urban population, annual population increase, percentage of population under 15, and life expectancy: Encyclopedia Britannica; 2013 World Population Data Sheet (Population Reference Bureau)

For political systems: Based on information from Freedom in the World, an annual publication of Freedom House (a nonprofit human rights organization), and the Freedom House website (freedomhouse.org); Encyclopedia Britannica; the U.S. State Department and its website (state.gov); and news accounts

For heads of government: Based on information from the GeoCities "Rulers" website (rulers.org); the State Department and its website; The World Factbook 2013 (C.I.A.); and news accounts

For capital, languages, date of...