LESZNO, Poland - In 1918, as the first World War wound down, a new war was just beginning - it was a war for national self-determination, against a country that had occupied the region for nearly 125 years. The war between Poland and Germany was known as the Greater Poland Uprising of 1918-19.On Jan. 17, the citizens of Leszno, Poland gathered in their town square to remember that uprising and celebrate the day, 97 years ago, when the German occupation of Poland ended.The celebration consisted of speeches, a military parade, fireworks and static displays from the Polish Armed Forces."This is the most important celebration for our city," said Tomasz Szymanski, the cultural and support manager for Leszno. "It celebrates the day when we became free from foreign occupation."The uprising came about because of disputes over Poland's borders. Most of Poland had been annexed to Prussia in the late 18th Century and was, at the end of World War I, still part of Germany.Poland became a country after WWI largely due to then U.S. President Woodrow Wilson's insistence on national self-determination as one of the ways to secure a "just and secure peace."With that in mind, Polish Maj. Gen. Jaroslaw Mika, commander, 11th "Lubuska" Armored Cavalry Division invited Soldiers from Headquarters and Headquarters Company, 3rd Armored Brigade Combat Team, 4th Infantry Division to take part in the celebration."It was really cool being here, the fireworks were great," said Staff Sgt. Kristina Bajis. "I really liked seeing their air defense weapons because I am in aviation."Soldiers from the "Iron Brigade" out of Fort Carson, Colorado, have rotated to Eastern Europe as part of continuous, "heel to toe" troop rotations to bolster ties with NATO allies. U.S. forces have been training in Poland since 2014 as part of Operation Atlantic Resolve.