Spontaneous parades broke out all over Washington the week after Gen. Robert E. Lee surrendered. Partygoers sang a two-year-old song, “When Johnny Comes Marching Home; Soldier’s Return March.” The instant hit was penned by Louis Lambert, a pseudonym of Patrick Sarsfield Gilmore.

“When Johnny comes Marching Home Again, Hurrah, hurrah!
We’ll give him a hearty welcome then, Hurrah, hurrah!
The men will cheer, the boys will shout, The ladies, they will all turn out,
And we’ll all feel gay, When Johnny comes marching home”

Source: Library of Congress