Houston was founded in 1836 on land near the banks of Buffalo Bayou (now known as Allen's Landing) and incorporated as a city on June 5, 1837. The city was named after former General Sam Houston, who was president of the Republic of Texas and had commanded and won at the Battle of San Jacinto 25 miles (40 km) east of where the city was established. The burgeoning port and railroad industry, combined with oil discovery in 1901, has induced continual surges in the city's population. In the mid-twentieth century, Houston became the home of the Texas Medical Center—the world's largest concentration of healthcare and research institutions—and NASA's Johnson Space Center, where the Mission Control Center is located.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"):  When was the City of Houston unincorporated?
unanswerable