The 24-year veteran of the Army Reserves stationed at Fort Sam Houston woke up early and put his plan into action.
"I've done it a couple of times," Williams said. "It just makes me feel good to honor the dead."
Far from Ground Zero, the Pentagon and the field in Shanksville, Pa., his moving 9/11 tribute unfolded before thousands of motorists driving along Interstate 10 in San Antonio.
"I went to Lowe's down the street, bought this flag pole and the flag," Williams said. "I got my uniform on and came out here and decided, 'Let's pay tribute to the fallen.'"
- SLIDESHOW Click here to see photos of the tribute
Setting up command on the Medical Drive bridge over the highway, Williams paced back and forth in full uniform with his flag. Even during a heavy downpour, the soldier let the rain fall in his face. He kept marching.
"I'll go until my legs and back won't let me anymore," he said.
Slowing down only to salute passing vehicles, Williams' steady, poignant tribute continued for hours. With each honking horn of an appreciative driver, Williams directed the attention back to the mission.
"I'm very appreciative of the men and women who lost their lives on that day," he said. "My heart goes out to their families."
It was a simple act by a single soldier that touched the heart of Military City USA.