Marriage license
Getting a marriage license in Gregg County
Both of you need to show up in person at the County Clerk's office, on the second floor of the courthouse at 101 E. Methvin, Suite 200, in Longview, and you'll want to call ahead for an appointment at (903) 236-8430 rather than just walk in. Bring real ID: a driver's license, passport, or a certified birth certificate (a hospital souvenir record won't do), plus your Social Security numbers. The license runs $81, cash or credit only.
Then comes the wait most people forget about. Texas makes you sit 72 hours between buying the license and getting married, so a Friday-afternoon license can't be used for a Saturday wedding. Active-duty military are exempt from that wait. Once you do marry, you have 90 days to use the license before it expires.
If either of you was recently divorced, there's a separate 30-day wait after the divorce is final before a new license can issue, unless you're remarrying the same person. And since September 2017, anyone under 18 needs a court order; the clerk can't issue to a minor on a parent's signature alone. If your situation has a wrinkle like that, sort it out with the clerk before the calendar gets tight.
Source to confirm: Gregg County — Marriage License Information