The executive order President Donald Trump signed today to immediately begin planning to construct a wall along the U.S.-Mexico border follows his signature campaign promise to stem the flow of illegal immigration and drugs into the country.

“immediate construction of the border wall”

Jan. 25, 2017

“The secretary of homeland security, working with myself and my staff, will begin immediate construction of a border wall. So badly you needed – you folks know how badly needed it is as a help – but very badly needed. ”

Details remain fuzzy on what ultimately might be built, though Trump repeatedly has insisted it will be “a wall, not a fence,” and he says he can get it done because “nobody builds walls better than me.”

Trump has said this barrier can be built for as low as $8 billion and has argued that Mexico will pay for it. An internal estimate by U.S. Customs and Border Protection for 700 miles of the 2,000-mile border pegs the cost at $15 billion to $20 billion, plus another $500 million to construct access roads.

Earlier this week, Reveal from the Center for Investigative Reporting published a detailed map of the current border fence. Former border officials also told us that existing sections of the current fence would benefit from upgrades and more modern materials. Large swaths of the land between the countries, they say, don’t need a barrier because of the remoteness, topography or dearth of illicit activity. Two top leaders of a Bipartisan Policy Center task force on immigration said this week that focusing on the incentives that draw undocumented workers is a more effective way to curb illegal immigration than a massive border wall.

Trump has talked about the wall from day one of his campaign, though the details have varied.

Trump launches campaign: “I would build a great wall”

June 16, 2015

“I would build a great wall – and nobody builds walls better than me, believe me – and I’ll build them very inexpensively.”

“This wall is going to have a big, beautiful, open gate”

Sept. 17, 2015

“People aren’t going to Home Depot and buying a ladder and walking right off – not this wall. And by the way, this wall is going to have a big, beautiful, open gate.”

“It will be a real wall”

Sept. 28, 2015

“It’ll actually be a wall that will look good — believe it or not, ’cause what they have now is a joke. They’re ugly, little and don’t work.”

“We need a thousand” miles

Feb. 9, 2016
https://www.youtube.com/watch?v=vNaSY0Ehalg?t=4m57s
“The wall is probably $8 billion, which is a tiny fraction of the money that we lose with Mexico. … I’m very good at this.”

“Who is going to pay for the wall?” “Mexico!”

July 13, 2016
https://www.youtube.com/watch?v=HntQdpS0xGg?t=22m54s
“They’ll be happy to pay for the wall.”

“The drugs are pouring into our country”

Dec. 9, 2016
https://www.youtube.com/watch?v=bcqIooEQsjo?t=41m56s
“We will build the wall, and we will put an end to illegal immigration and stop the drugs from pouring into our country.”

“We’re going to work on the wall, Paul”

Dec. 13, 2016

“Somebody said the other day, ‘Well, now that Trump won, he’s really not going to build the wall.’ ”

“It’s not a fence. It’s a wall.”

Jan. 11, 2017
https://www.youtube.com/watch?v=W4Tu90xYFaM?t15m21s
“I could wait about a year and a half until we finish our negotiations with Mexico, which we’ll start immediately after we get to office, but I don’t want to wait.”

“The wall is getting designed right now.”

Feb. 8, 2017

“The wall is getting designed right now. A lot of people say, oh, oh, Trump was only kidding with the wall. I wasn’t kidding. I don’t kid. I don’t kid. I watch this, and they say I was kidding. No, I don’t kid. I don’t kid about things like that, I can tell you. No, we will have a wall. It will be a great wall, and it will do a lot of — will be a big help. Just ask Israel about walls. Do walls work? Just ask Israel. They work — if it’s properly done.”

Andrew Becker is a reporter for Reveal, covering border, national and homeland security issues, as well as weapons and gun trafficking. He has focused on waste, fraud and abuse – with stories ranging from border corruption to the expanding use of drones and unmanned aerial vehicles, from the militarization of police to the intersection of politics and policy related to immigration, from terrorism to drug trafficking. Becker's reporting has appeared in The Washington Post, the Los Angeles Times, The New York Times, Newsweek/The Daily Beast and on National Public Radio and PBS/FRONTLINE, among others. He received a master's degree in journalism from UC Berkeley. Becker is based in Reveal's Emeryville, California, office.

David Rodriguez is a community engagement producer for Reveal. Before joining Reveal, Rodriguez's work as an engagement assistant producer at Southern California Public Radio helped develop a report on how newsrooms can improve their reporting on the 2020 Census, which won the 2019 Gather Award in Engaged Journalism. 

Rodriguez has reported stories on immigration at the Investigative Reporting Workshop in American University. He is an alum of NPR's Next Generation Radio and San Francisco State University. He previously completed internships with KPCC's podcast team, where he helped produce The Big One: Your Survival Guide, and with Reveal, where he created a database tracking how much money and time the United States government has spent buying land along the U.S.-Mexico border. He is based in Los Angeles.