Last Friday, the Dept. of Homeland Security, Customs and Border Protection posted a preliminary solicitation for firms interested in designing and building the controversial border wall along the southern U.S. border.

Less than a week later, more than 225 firms have responded to the solicitation, according to The Hill. This includes 20 firms owned by Hispanic Americans.

According to DefenseOne.com, interested firms include a few “corporate titans, among them Raytheon, a defense contractor,” and Caddell, “a construction company with a global portfolio.”

In addition, “dozens of companies described themselves as minority owned, veteran owned, or small disadvantaged businesses” have responded to the solicitation.

While the wall remains a politically controversial topic, Shawn Moran, the vice president of the National Border Patrol Council has stated a wall would be a “vital tool” in enforcing our nation’s borders.

In fiscal year 2016, the Department of Homeland Security apprehended 530,250 individuals nationwide, according to a DHS press release. That number included 415,816 apprehensions by the U.S. Border Patrol (USBP).

Despite the estimated cost of between $15 and $25 billion to build the wall, if the wall does as expected, it is likely to pay for itself almost immediately upon completion.

President Trump hopes to have the wall built by the end of his first term.

Contractors who have expressed interest in the project have until March 10 to submit a prototype concept paper, followed by a formal request for proposal by March 24, notes The Hill.

UPDATE: Mexico’s Cemex, one of the largest cement producers in the world, has also stated it would participate in building the wall.

“We will gladly do it,” Cemex President Rogelio Zambrano told the daily newspaper Reforma, when asked if the company would provide a cement estimate for the controversial project.