On the face of it, the promise of the wall along the US-Mexico border will be one that United States President Donald Trump will find impossible to keep.
Texas' Rio Grande river makes up about half of the entire 3,058km-long US-Mexico border. Much of the land on the US side was part of Mexico before the 1846-1848 Mexican-American war.
The wall would have to be on the American side of the river - which means it will slice through privately owned land. This may split the land in some cases or leave some owners between wall and river.
Many here in the Rio Grande Valley hope the wall will not be built. The expensive project will not solve the issue of illegal immigrants and will have a disastrous environmental impact on a low-lying delta area prone to flooding, they say.
Mrs Pamela Taylor, 88, and her late husband settled down in an area of Brownsville a short walk from the Rio Grande river in 1947.
"The wall will not impact my personal life," Mrs Taylor told The Straits Times, while sitting on her leafy patio with mockingbirds calling from the trees.
"But it's not going to do the job. It's a waste of money. We have kids who can't afford to go to college. We have people with medical problems who can't afford medical help. We have veterans who can't afford hospitals. So why waste money? It's ridiculous."
The wall will not impact my personal life. But it's not going to do the job. It's a waste of money. We have kids who can't afford to go to college. We have people with medical problems who can't afford medical help. We have veterans who can't afford hospitals. So why waste money? It's ridiculous.
MRS PAMELA TAYLOR, 88, who settled in an area of Brownsville, a short walk from the Rio Grande river, in 1947.
Through the decades, Mrs Taylor has seen immigrants coming across the border. At night when her dogs barked, it often meant there were immigrants running through the cornfield in front of her house. Once, a pregnant woman climbed over her fence - and went into labour in her front yard. But that was then.
In recent years, she has also found drugs around her property - even a car full of half a million US dollars worth of drugs - left behind by runners for the notorious Gulf Cartel in Matamoros on the Mexico side of the Rio Grande.
The cartel also traffics in people, charging between US$4,000 (S$5,500) and US$8,000 for each desperate immigrant - increasingly from Central American countries mired in poverty and violence - to cross into the US.
The Texas-Mexico border is already one of the most heavily policed peacetime borders in the world. Electronic eyes keep watch around the clock. Armed US Border Patrol agents in sturdy sport utility vehicles sit at strategic locations or trundle up and down dirt roads that run roughly parallel to the Rio Grande - called the Rio Bravo in Latin America.
Sometimes, a US Border Patrol agent parks outside Mrs Taylor's house. "I can't go out of my home without them knowing," she said.