North America metropolitan area by population in North America: Greater Mexico City. Canada also breaks into the top ten largest metropolitan areas with the Toronto metropolitan area having six million people. The proximity of cities to each other on the Canada–United States border and Mexico–United States border has led to the rise of international metropolitan areas. These urban agglomerations are observed at their largest and most productive in Detroit–Windsor and San Diego–Tijuana and experience large commercial, economic, and cultural activity. The metropolitan areas are responsible for millions of dollars of trade dependent on international freight. In Detroit-Windsor the Border Transportation Partnership study
North America alongside English. Christianity is the largest religion in the United States, Canada and Mexico. According to a 2012 Pew Research Center survey, 77% of the population considered themselves Christians. Christianity also is the predominant religion in the 23 dependent territories in North America. The United States has the largest Christian population in the world, with nearly 247 million Christians (70%), although other countries have higher percentages of Christians among their populations. Mexico has the world's second largest number of Catholics, surpassed only by Brazil. A 2015 study estimates about 493,000 Christian believers from a Muslim background in North America, most