1836
Battle of the Alamo
The setting
San Antonio de Bexar, Texas
Fortified former mission compound with low, incomplete walls
Reveal the outcome
Recorded sideMexico (Centralist Army)
Recorded resultVictory; stormed the fort
Mexican victory; total loss of the Texian garrison
How the atlas explains it
This was a doomed last stand, not a win: heavily outnumbered defenders behind weak walls, with no relief coming, were overwhelmed in a pre-dawn assault and killed almost to a man. Its 'success' was purely moral and temporal, tying down Santa Anna's army for nearly two weeks.
What followed
The massacre, honestly a decisive Texian defeat, became the rallying cry 'Remember the Alamo!' that galvanized recruitment and hardened resolve for the campaign that ended at San Jacinto.