Short answers, pulled from the story.
Lieutenant Colonel Alexander C. W. Fanning led the 4th U.S. Artillery to establish Fort Gatlin on the 9th of November 1838. The fort was named for Army physician John S. Gatlin who died in Dade's Massacre on the 28th of December 1835.
Orlando was originally called Jernigan after Isaac and Aaron Jernigan acquired land northwest of Fort Gatlin along Lake Holden in July 1843 under the Armed Occupation Act. The post office moved from Jernigan to Orlando at a new location in present-day downtown Orlando in 1857 following a town meeting debate about the name.
The Great Freeze of 1894 forced many independent citrus grove owners to give up their holdings which consolidated operations into the hands of few citrus barons. This event caused many residents including Orlandoans to move elsewhere mostly to North California or the Caribbean while shifting operations south primarily around Lake Wales in Polk County.
Walt Disney World opened in October 1971 after Walt Disney announced plans to build the resort in 1965. Orlando was selected because its inland location exposed it to less hurricane threat than coastal regions like Miami and Tampa despite not being free from hurricane damage.
More than 100 people were shot at Pulse a gay nightclub in Orlando with fifty including the gunman killed and sixty wounded. The gunman identified as 29-year-old Omar Mir Seddique Mateen pledged allegiance to the Islamic State before police SWAT team members shot him to death.