Complex sentence: Although historians generally agree that the Articles were too weak to hold the fast-growing nation together, they do give Congress credit for resolving the western issue, as the states voluntarily turned over their lands to national control.
Split into simpler sentences: Although historians generally agree that the Articles were too weak to hold the fast-growing nation together, they do give Congress credit for resolving the conflict between the states over ownership of the western territories. The states voluntarily turned over their lands to national control.