American flags not made in America are now banned from U.S. military installations, reports CBS News.

California Rep. Mike Thompson, a Vietnam War veteran and Purple Heart recipient, wrote the legislation that requires any flag purchased by the Defense Department to be 100-percent made in America.

"I thought it was appalling our Department of Defense would have flags made in other countries," Thompson, told CBS News after the legislation was signed into law earlier this week.

In the aftermath of 9/11, Americans purchased so many flags to fly on their homes or cars that U.S. manufacturers could not keep up with the demand.

China stepped in and has since then become the largest supplier of American flags, according to the Flag Manufacturers Association of America. In 2012, approximately 3.6 million dollars was spent on importing American flags to the U.S. from China.

“I am proud to have worked to pass this law so that our men and women in uniform never have to fight under a U.S. flag made overseas, and so that our Defense Department never again spends American tax dollars on a U.S. flag made overseas,” Thompson said to CBS News.

While U.S. bases will receive new all-American flags, federal agencies will continue to fly foreign-made banners due to expensive production prices.