The U.S.-China trade war has begun. Here’s how things got to this point.

With all the recent hostilities, it's easy to forget that China and the United States have been top trading partners for years.

In 2015, China overtook Canada as the United States' largest trading partner, boasting nearly $500 billion in total imports and exports, about 15 percent of total U.S. trade. The United States, on the other hand, has been China's top trading partner since the 1990s, overtaking Hong Kong as the largest importer of Chinese merchandise goods in 1998.