Complex sentence: Buell made excuses that the Army of the Ohio's march overland toward Pittsburg Landing was hindered by "swollen rivers" and rain, and many newspapers and some Federal soldiers credited Buell with "saving" Grant in the battle.
Split into simpler sentences: Buell made excuses that the Army of the Ohio's march overland toward Pittsburg Landing was hindered by "swollen rivers" and rain. While acknowledging these delays with criticism, many newspapers and some Federal soldiers credited Buell with "saving" Grant in the battle.