The 300 U.S. Immigration and Customs Enforcement agents expected to arrive in the Chicago area will be based at Naval Station Great Lakes in North Chicago. The site could also host the National Guard. If President Donald Trump follows through on his threat to send guard members to Chicago — over the objections of Gov. JB Pritzker and Mayor Brandon Johnson — then it would be unprecedented.

For those who have not passed through the gates of the installation, Great Lakes plays a key role in the 250-year-old United States Navy. It is its only “boot camp,” which is where new recruits from around the country gather for processing, classes and skills training before they can be recognized as sailors. Famous graduates include George Halas, Chicago Bears founder and coach; Carl Brashear, the Navy’s first Black master chief diver; and siblings from Waterloo, Iowa, known as the “Fighting Sullivan Brothers.”

Here’s a look back at how the facility came to be and its mission through times of war and peace.

Dec. 13, 1902

Though the exact site had not yet been determined, Navy officials concluded the Chicago area was the best location for a new naval training facility due to its “strategic value, its ease of defense, and because it was the center of population and would furnish a large number of men, which is necessary to the success of the new institution,” the Tribune reported.

Due to the large number of enlistments in neighboring states, it had been suggested to the House Committee on Naval Affairs in late January 1902 that a training center near Chicago might be a good idea.

Nov. 24, 1904

After a lengthy vetting process, Lake Bluff was unanimously chosen as the location for a naval training station. Officials recognized that the Navy couldn’t just depend on recruits with knowledge of the seas to enlist — it also needed volunteers from landlocked parts of the middle U.S. Rather than risk desertion by taking those landlubbers immediately out to sea, the training center would gradually acclimate them to their new environs.

“A recruit could best be prepared for his new duties ashore, or at least on the coast line, where he could learn his new duties gradually and become amphibious, so to speak, before making a final plunge into the blue way of the water,” the Tribune reported.

About 172 acres was donated by Chicago business owners for the site on which the training station would be constructed at a cost of more than $2 million (or roughly $70 million in today’s dollars).

A few other pluses for the suburban Chicago location: It was relatively ice-free during the winter and didn’t share any borders with Canada — in case of war with the northern neighbor.

July 1, 1911

The naval station was commissioned with 39 buildings and the capacity for 1,500 recruits. Two days later, the first to enlist was Joseph W. Gregg, 17, of Terre Haute, Indiana.

Oct. 28, 1911

President William Howard Taft was present for the dedication of the training station and the first graduation of 300 sailors, including Gregg. In his 10-minute speech, Taft spoke about the good relations shared between the U.S. and Canada — as if to calm any fears the installation might violate the Rush-Bagot Treaty, which limited naval arms on the Great Lakes after the War of 1812.

“We have no fort, no forces, no navy here, because we know there is no danger in that direction, and we offer that undefended border on both sides to illustrate the possibility of neighbors living in permanent amity and peace,” Taft said.

Not among the celebration were crates of wine sent to the facility by the brother of Rear Admiral Albert Ross. The senior naval official sent them back unopened.

“President Taft and his party will have nothing stronger than lemonade while they are my guests,” The New York Times reported Ross told his brother about the returned shipment.

World War I

More than 125,000 recruits passed through Great Lakes.

Recruitment slowed to a crawl after the war’s end, with just an air base and radio school in operation.

World War II

More than 1 million recruits were trained at Great Lakes between Dec. 7, 1941 (the day Pearl Harbor was attacked), and Aug. 14, 1945 (Victory over Japan Day).

The Navy began accepting Black enlistments for general service in 1942. They were trained at Camp Robert Smalls, which was the part of Great Lakes designated for Black recruits. Black men weren’t allowed to participate in officer training, though, until January 1944 — when there were already 100,000 Black sailors in the Navy.

The first 16 men who were accepted into the program passed their exams with scores so high, they were forced to retake them. That’s when, according to the Navy, they scored even higher, with an average grade of 3.89 out of 4 — the highest average of any class in Navy history at the time. The Navy, however, only commissioned 12 as officers. A 13th was made a chief warrant officer, hence the nickname “The Golden Thirteen.”

Today, every recruit enters the installation through the Golden Thirteen Recruit Inprocessing Center, which opened in 1987.

March 12, 1993

Great Lakes was proposed as the Navy’s only basic training site in the U.S. as part of post-Cold War budget cuts.

Defense Secretary Les Aspin announced the closure of 31 military bases in the next six years — including the Navy’s training centers in San Diego and Orlando, Florida. A federal panel agreed in June 1993.

Also affected by Aspin’s closures was Glenview Naval Air Station, and the Air Force Reserve Station at O’Hare International Airport. A total of 1,900 reservists from Air Force Reserve and Illinois Air National Guard units at O’Hare would be affected by the cuts, the Tribune reported.

1994

The facility was opened to women for the first time.

Today, Great Lakes occupies more than 1,600 acres and has more than 1,150 buildings.