What was the significance of the first section of the 14th amendment to Reconstruction?

Answer 1

It made everyone born in or naturalized by the United States a full citizen. As such they cannot be slaves.

http://en.wikipedia.org/wiki/Fourteenth_Amendment_to_the_United_States_Constitution#Text

Answer 2

but why was this significant during reconstuction?

Answer 3

This article explains more.

http://www.pbs.org/wnet/jimcrow/stories_events_14th.html