Yes, he said the aim was to dedicate the land for the fallen soldiers But he does not actually contradict himself when he said that the living cannot consecrate the ground. If you look at the next sentence following that, he explains that it is the brave men, living and dead who have consecrated it already far beyond the ability of the living.
"But, in a larger sense, we can not dedicate -- we can not consecrate -- we can not hallow -- this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract."
He went on to explain the role of the living was to be dedicated to the task that those men's sacrifice would not be in vain.
http://www.loc.gov/exhibits/gadd/images/Gettysburg-2.jpg
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