Complex sentence: Although Grant suffered severe losses during the campaign, it was a strategic Union victory, causing Lee's army to suffer proportionately higher losses and maneuvering it into a siege at Richmond and Petersburg, Virginia, in just over eight weeks.
Split into simpler sentences: Although Grant suffered severe losses during the campaign, it was a strategic Union victory. It inflicted proportionately higher losses on Lee's army and maneuvered it into a siege at Richmond and Petersburg, Virginia, in just over eight weeks.