Question: Which of the serious defeats for the Union came first in the American Civil War: the Battle of Chickamauga or the Battle of Fredericksburg?
Sentence (from "Battle of Fredericksburg"): The Union Army's futile frontal attacks on December 13 against entrenched Confederate defenders on the heights behind the city are remembered as one of the most one-sided battles of the war, with Union casualties more than three times as heavy as those suffered by the Confederates.
Relevant evidence: No