Complex sentence: The terms of the contract involving titles and the retention of property by the company lead to problems between settlers and the company for many years requiring additional legislation by the Congress of the Republic of Texas and the legislature of the State of Texas.
Split into simpler sentences: The terms of the contract involving titles and the retention of property by the company lead to problems between settlers and the company for many years. These problems required additional legislation by the Congress of the Republic of Texas and the legislature of the State of Texas.