Complex sentence: During a brief stopover at Fort Monroe he detected an unusual buildup of shipping in Hampton Roads and learned they were carrying thousands of troops under Ambrose Burnside from North Carolina on their way to reinforce John Pope in the Northern Virginia Campaign.
Split into simpler sentences: During a brief stopover at Fort Monroe he detected an unusual buildup of shipping in Hampton Roads. He found they were carrying thousands of troops under Ambrose Burnside from North Carolina on their way to reinforce John Pope in the Northern Virginia Campaign.