Two major events coincided with Charles's new course in home affairs and with his discreet exploration of the chances of a separate peace: the Russian Revolution (March 1917) and the U.S. declaration of war on Germany. In May 1917 Masaryk left London for Russia to speed up organization of a Czechoslovak army. While small units of volunteers had been formed in the Allied countries during the early part of the war, thousands of prisoners of war were now released from Russian camps and trained for service on the Allied side. A Czechoslovak brigade participated in the last Russian offensive and distinguished itself at Zborov (Ukraine) in July 1917. From the United States came moral encouragement, but U.S. President Woodrow Wilson's early statements pertaining to the peace aims were rather hazy. Several weeks after the United States declared war on Austria-Hungary, President Wilson promulgated his celebrated Fourteen Points (January 1918), the 10th of which called for “the freest opportunity of the autonomous development” of the peoples of Austria-Hungary. After the Russian Revolution, Czechoslovak troops became involved in struggles between the Bolsheviks and the conservative forces for the control of the Siberian railroad. Their achievements, noticed favourably by the Western governments and press, gave the Czechoslovak cause wide publicity and helped its leaders to gain official recognition. Masaryk left Russia for the United States, where, in May 1918, he gained solid support from Czech and Slovak organizations. A declaration favouring political union of the Czechs and Slovaks was issued at Pittsburgh, Pa., on May 31, 1918 (called the Pittsburgh Convention). Throughout 1918, dealings with the Allies progressed more successfully. Added to the favourable publicity of the Siberian campaigns were increased activities at home to get the struggle for independence endorsed by the Allied governments. A demand for a sovereign state “within the historic frontiers of the Bohemian lands and of Slovakia” was made in Prague at the Epiphany Convention (January) and repeated later with more vigour. In May not only the Czechs but also the Slovaks made statements to which Masaryk and his collaborators could point when pressing for an official recognition. The anti-Austria resolution, adopted at the Congress of Oppressed Nationalities at Rome (April), helped in disarming conservative circles in the Allied countries who opposed a total reorganization of the Danubian region.