George Mifflin Dallas grave at St. Peter's Church in Philadelphia, Pa; see my Texas page on http://www.flagguys.com
From Wikipedia: "George Mifflin Dallas (July 10, 1792 – December 31, 1864) was a U.S. Senator from Pennsylvania and the eleventh Vice President of the United States, serving under James K. Polk. " From the Dallas Historical Society "For Whom Was Dallas Named? Over the years, there has been a lot of debate about the name Dallas. We know that Dallas County was named for George Mifflin Dallas, vice president of the United States at the time of annexation. However, all that is known about the origin of Dallas for the name of the city is that John Neely Bryan named it for "his friend, Dallas" There are several candidates for whom this friend might be.

The town was known as Dallas early in 1842. At that time, George Dallas was a practicing lawyer in Philadelphia. He had never been very far west, and Bryan had never been very far east, so it's doubtful they ever met. One theory is that the town was named for Commodore Alexander Dallas, a brother of George, who was combating piracy in the Gulf of Mexico. Another theory is that the town was named for Walter Dallas, who fought in San Jacinto, or his brother, James, a former Texas ranger. After the war, they had received land grants in McLennan, Hill, and Burleson counties, which are close enough that Bryan might have know them. Yet another candidate is Joseph Dallas who came to Cedar Springs in 1843, from Arkansas. It is assumed that they knew each other in Arkansas, and Bryan invited his friend to Texas. However, the truth is that no one is sure whom Dallas is named for, and the answer will probably never be discovered"