The Lure of the Rio Grande Valley (1927) Brownsville experienced a population boom in the early twentieth century, with the population soaring from just over 6,000 in 1900 to 22,021 in 1930. Leading the expansion were land agents from the area traveling north to entice land seekers to the Valley, playing up the agreeable weather and available farmland. This 1927 promotional film targets Chicagoans looking for a winter home or warmer climate.