Complex sentence: All of this before it ultimately became a part of the Louisiana Purchase, which had James Monroe & Robert Livingston acting as real estate agents to the largest land transaction in history, for the bargain-basement sum of $11,500,000.00.
Split into simpler sentences: All of this, before it ultimately became a part of the Louisiana Purchase. An acquisition which had James Monroe & Robert Livingston acting as real estate agents to the largest land transaction in history, for the bargain-basement sum of $11,500,000.00.