The Market’s Response to the U.S. declaration of War on Germany During World War I On April 6, 1917 the United States broke the isolationist camp and declared war on Germany. The market was not thrilled. The market would not revisit pre-declaration levels until a few months after the end of the War (November 1918). Share this:TwitterFacebookGoogleLike this:Like Loading... Leave a Reply Cancel reply Enter your comment here... Fill in your details below or click an icon to log in: Email (required) (Address never made public) Name (required) Website You are commenting using your WordPress.com account. ( Log Out / Change ) You are commenting using your Google+ account. ( Log Out / Change ) You are commenting using your Twitter account. ( Log Out / Change ) You are commenting using your Facebook account. ( Log Out / Change ) w Cancel Connecting to %s Notify me of new comments via email.