A timeline of unfulfilled promises Trump made about his border wall, a cornerstone of his 2016 campaign which has faded from view in 2020

• Since long before his presidency, Donald Trump has made the construction of a wall along the border with Mexico his keystone issue.
• Since it was first suggested — to rapturous applause — in 2014, the issue has arguably propelled Trump into the presidency.
• The Washington Post reported that Trump mentioned a wall more than 200 times in his 2016 campaign, though it has played only a bit part in 2020.
• Trump has made a dizzying array of claims about it. However, there is still no manmade physical barrier along much of the US-Mexico border.
• Here are some of the key claims he has made about the wall that have not come to pass.

Donald Trump's vision of a "big, beautiful wall" between the US and Mexico arguably did more than anything else in his 2016 platform to propel him into the White House.

Border security experts, and many of Trump's allies, have pointed out that a wall alone is too blunt an instrument to help much with US border security issues.

But the architect of the policy, Sam Nunberg earlier explained to Business Insider that this lack of subtlety is exactly the point.

"The wall in 2016 was symbolic of Donald Trump: common sense, practical solutions, simplified answers — as opposed to long nuanced, detailed policy speak," he said

Trump recently told a rally that the wall is "almost complete" — while his campaign website says 216 miles have been completed. It does not mention that the US-Mexico border is almost 2,000 miles long.

Here is a run-down of the major promises the president has made about the wall.

April 2014: "I would build a border like nobody's seen before."

In April 2014, as Trump prepared to begin his bid for the Republican nomination, he made his first mention of a wall — or at least a fence — at a New Hampshire conservative event.

In preparing for his speech to the Freedom Summit, advisers Sam Nunberg and Roger Stone struggled to remind Trump to center immigration in his speech. Trump was resolving to be "the hardest on the Right" on these issues, Nunberg later told Business Insider, but struggled to stick closely to prepared notes.

The simple idea of a wall appealed to Trump.

"We either have to have borders, and I mean strong borders ... and I mean strong. And you know I'm a builder, I build great buildings," Trump told his audience.

"Building a border, you know they talk about 'oh I don't know, how could we possibly build a fence that nobody can climb over?' I would build a border like nobody's seen before. Nobody's climbing over."

June 2015: "I will make Mexico pay for that wall."

As Trump announced his candidacy for the Republican nomination, a new promise arose — and it appears to have been totally off the cuff.

"I will build a great, great wall on our southern border, and I will make Mexico pay for that wall," he said. "Mark my words."

According to Ian Volner, who has chronicled the Trump wall in his book "The Great Great Wall: Along the Borders of History from China to Mexico," the claim wasn't in the briefing notes circulated to journalists prior to his announcement speech.

His campaign quickly wound it back, qualifying the promise as it made headlines.

Whether Mexico was paying literally or figuratively didn't turn out to matter that much. According to The Washington Post, Trump would go on to talk about a border wall more than 200 times on the tumultuous 2016 campaign trail.

August 24, 2015: It will have a "very big, beautiful door"

"This will be a wall with a very big, very beautiful door, because we want the legals to come back into the country," Trump told CBS News.

A big door to welcome documented immigrants hasn't been given much attention since. In a 2019 roundtable discussion on border security, Trump remarked on the doorways in an existing section of wall and suggested not having any.

"Because putting the doors on cost more than the property is worth," he said.

January 25 2017: He orders "a contiguous, physical wall" (or similar barrier).

Anti-immigration executive orders came at speed after Trump took office.

The Border Security and Immigration Enforcement Improvements set in officialese exactly what Trump meant by the wall — a definition that left room for the many, many visions the president has described since.

"'Wall' shall mean a contiguous, physical wall or other similarly secure, contiguous, and impassable physical barrier," read the order. With numerous natural barriers along the way, the amount of new construction has been reckoned at around 900 miles.

June 6, 2017: "There is a chance that we can do a solar wall."

With this environmentally-friendly vision, proposed at a White House meeting with Republican congressional leaders, Trump suggested the costs of the wall could be covered by solar-power-generated electricity.

"We are seriously looking at a solar wall," said Trump, pointing out that the sun-drenched border would offer obvious opportunity.

As Business Insider's Leanna Garfield reported at the time, a solar-powered array could conceivably recuperate construction costs, but only over decades.

It was never mentioned again.

July 7 2017: Mexico will "absolutely" pay. This time, said with the Mexican president sitting next to him.

It's not possible to list all the times Trump has repeated his claim that Mexico will foot the bill for the wall, but The New York Times made a fact-check of the different ways that this could be done. These suggestions have ranged from cutting foreign aid to waiting for a literal check.

Trump said it again during a G20 press conference in Hamburg with Mexican president Enrique Peña Nieto did nothing to bring that closer to reality.

As of time of publication, an official Trump campaign page called "Promises Kept" makes no mention of ways in which Mexico has, or will, contribute.

April 2017: The wall will cost $21.6 billion

In 2017, the Department for Homeland Security priced the wall at $21.6 billion, Reuters reported.

Others disagreed. The Democratic Party asserted it would be at least $70 billion — plus maintenance costs — while a non-partisan oversight committee simply said the DHS costing was far too low.

January 2018: He'll build it for even less than that, in a year

After another estimate suggested the wall would cost $18 billion, Trump ramped up expectations still further.

During an immigration policy negotiation with Democrats, he said: "I can build it for less than that ... We can build the wall in one year and we can build it for much less money than what they're talking about," according to MailOnline.

He went on to talk about the Wollman Rink, an ice rink languishing under failed municipal repair and a spiraling budget until 1986, when he offered to take over the refurbishment. He completed it in four months and 25% under budget.

However, with the scrutiny of Congress, he has not been able to repeat this success with his border wall.

December 21, 2019: Government shutdown

In mid-December, as Congress was wrangling with the president over the next year's funding bill, Trump made a late-notice demand for $5 billion for his wall — much more than the $1.6 billion that the Democrats countered with for general border-security funding.

The standoff triggered a government shutdown that lastest well into the new year.

Trump begrudgingly agreed to a package including $1.4 billion for barrier construction on January 15, ending the shutdown.

January 10, 2019: No wall, renewed talk of Mexico paying

A year after his self-imposed deadline, there was no completed wall. Instead, there were more attempts to salvage the idea that Mexico might foot the bill.

On January 10, Trump said: "When, during the campaign, I would say Mexico is going to pay for it, obviously I never said this and I never meant they're going to write out a check."

Instead, he said, Mexico will pay "indirectly," through renegotiated trade deals. As Business Insider's Bob Bryan explained, that's not how it works.

February 15, 2019: Trump declares a national emergency

After the debacle of the government shutdown, Trump's next move was to declare the situation at the border a national emergency, enabling him to bypass Congress and approve billions in funding for his wall.

As he announced it, he told reporters: "I could do the wall over a longer period of time. I didn't need to do this. But I'd rather do it much faster."

Another $3.8 billion was raided from the Pentagon's budget for the wall, which was considered a "higher priority item," NPR reported.

June 2020: Trump says Biden will finish the wall if he gets elected

With the project clearly not going to plan, and an election looming, Trump told Fox 10 in Phoenix that the wall would continue even if he loses.

He predicted that Joe Biden would have to continue the project or there would be a "revolution." Biden soon said the opposite: if he is elected, construction will stop.

August 18, 2020: "Almost complete" — even though it is far from it.

Trump, and his campaign, have made many different claims about how done the wall is. On the campaign trail on August 28, Trump told New Hampshire that the wall is "almost complete."

Yet on the Trump campaign website "Promises Kept," the wall's completion is discussed in the present tense.

"Pres. Trump is fulfilling his promise to build a border wall, with large portions finished or under construction," says the site.

The Trump campaign states that 216 miles have been completed, "with an additional 339 miles under construction and 183 miles under pre-construction." It is not clear what "pre-construction" is.

But what we do know is that most of that was a replacement wall. As of May 2020, only three miles has been built on fresh ground, The Washington Post reported.