Add spaces: ThepartyendedearlySundaymorning.

Answer: The party ended early Sunday morning.

Add spaces: TheBlackcountiesoftheDeltahadpoliticalpowerinproportiontotheirtotalpopulationbutthispowerwaswieldedbytheWhiteminority.

Answer: The Black counties of the Delta had political power in proportion to their total population but this power was wielded by the White minority.

Add spaces: Thesleevesareworkedfromarmholesanddown.

Answer:
The sleeves are worked from armholes and down.