What does Lincoln mean when he says soldiers gave "the last full measure of devotion"?

The Union defeated the Confederates at Gettysburg.

The soldiers fought bravely.

The soldiers gave their lives for the Union.

The Union is more important than the soldiers.

Question

What does Lincoln mean when he says soldiers gave "the last full measure of devotion"? 

 The Union defeated the Confederates at Gettysburg.

 The soldiers fought bravely.

 The soldiers gave their lives for the Union.

 The Union is more important than the soldiers.

anonymous · Answer

I am thinking The soldiers gave their lives for the Union. but it could be The soldiers fought bravely