Conversation so far:
What happpened at the velley and apomattox?
defeated the army of Confederate Lieutenant General Jubal Early in the Valley Campaigns of 1864.
How did they defeat the army?
CANNOTANSWER.
When did this take place?
1864.

Question: Was it in the winter?
Self-contained rewrite: Did the Valley and Appomattox 1864 take place in the winter?