Answer: The Arrival of Texas and Pacific Railway.
Step-by-step explanation:
Texas and Pacific Railway arrived in Fort Worth in the year 1876 at a time when Fort Worth was making a recovery in the cattle business.
Their subsequent arrival transformed simple stockyards to Nationwide famous centres for cattle trade.
With this newfound success people from all over the country especially other areas of the South which had suffered greatly in the Civil War came running to partake of the cake so to speak and in so doing increased the population.
Fort Worth also served as a conduit to other parts of the country by those same railroads so people around the area used it as a transportation centre as well.