The first four months of 1915 witnessed a titanic struggle on the Eastern Front, in East Prussia, the Carpathians, Bukovina, and at Przemysl. Both sides suffered staggering casualties that surpass those of the Somme or Verdun the following year. Ironically, the Austro-Hungarians lost far more men trying to save Przemysl than there were in the fortress.
By the late 19th century the US stretched from the Atlantic to the Pacific to the Arctic. From the 1890s though, a new wave of American expansion began that resulted in a vast overseas empire including the Philippines, Cuba, Haiti, Panama, Nicaragua, and more.
By the spring of 1915, the Western Front had bogged down into trench warfare. Allied offensives tried to break the deadlock in spring and fall 1915. The fall offensives were among the bloodiest of the war. After unprecedented bloodletting and use of munitions, the Western Front was still locked in a stalemate at the end of 1915.