Spectators at the 2015 Chicago Memorial Day parade take photos as one of the many floats, marching bands and JROTC units pass by the Chicago Theater May 23, 2015. The annual parade is considered one of the largest in the nation and attracts thousands of visitors each year to remember those who have paid the ultimate sacrifice for American freedom. - Spectators at the 2015 Chicago Memorial Day parade take photos as one of the many floats, marching bands and JROTC units pass by the Chicago Theater May 23, 2015. The annual parade is considered one of the largest in the nation and attracts thousands of visitors each year to remember those who have paid the ultimate sacrifice for American freedom.