When Confederate guns fired on Fort Sumter, the president of the United States quickly declared it an act of war. Abraham Lincoln not only immediately called out the militia of the states into federal service but also called the Congress into session.

Lincoln had run many times for office and lost most of the time, but he was no tyro at politics and symbolism. The Congress was called to meet on July 4, 154 years ago today.

The symbolism of July 4 and Union was powerful then, and it helped the first Republican president rally the nation. “Every man must be for the United States or against it,” added Stephen A. Douglas, Lincoln’s Illinois rival and leader of the national Democrats.

That quote, as noted by famed LSU historian William Cooper in his 2012 study “We Have the War Upon Us,” did not mean that politics was over. For the few months of life remaining to him, the ailing Douglas supported the Union but also was a political opponent of Republican policies he questioned.

That the politics of the United States did not end on that July 4 is a lesson. The divisions of the nation continue today over Confederate symbols and heroes of the past. Today’s date that had such an impact on our forebears ought to resonate with us, as we recognize what we have in common on July 4, this year and every year.