The U.S. was an important, but minority share market-cap country in 1899 (less than 20%). The U.K. was the big dog back then (more than 30%), and France was very significant as well (about 14%).
The U.S. reached about 70% between the end of World War II and the DotCom bubble. However, with rising market-cap elsewhere, including emerging markets, and including privatization of state enterprises in other countries, the U.S. is now about 45% of world stock market-cap.
Today, the U.K is under 9%, and Canada at 4% is larger than France.
The charts are from the Credit Suisse “2012 Yearbook”.