Conversation so far:
What branch of the Military was Tammy Duckworth in?
United States Army
When was Tammy Duckworth first deployed?
Tammy Duckworth was deployed to Iraq in 2004.
Where in Iraq was Tammy Duckworth based?
Was Tammy Duckworth injured while in the military?
She lost her right leg near the hip and her left leg below the knee.
What happened to cause Tammy Duckworth's injuries?
Duckworth's injuries were from when the UH-60 Black Hawk helicopter she was co-piloting was hit by a rocket-propelled grenade fired by Iraqi insurgents.
Did Tammy Duckworth recieve any medals?
Duckworth received a Purple Heart on December 3.

Question: When was she promoted to Lt Colonel?
Self-contained rewrite: When was Tammy Duckworth promoted to Lt Colonel?