A bill honoring a World War II-era intelligence service that served as the precursor to the CIA passed in Congress on Wednesday after a months-long holdup and despite the legislation’s overwhelming bipartisan support.

The bill, after it is signed into law by President Obama, will bestow the Congressional Gold Medal on the aging veterans of the Office of Strategic Services, or OSS. Although the bill had more than 320 co-sponsors in the House, a new set of congressional rules that prevented groups, as opposed to individuals, from receiving the medal kept it from passing until those rules were waived earlier this month. A companion bill in the Senate passed in March.

The rules, which passed at the start of the 114th Congress, required a waiver that had to be proposed by House Majority Leader Kevin McCarthy (R-Calif.) and approved by the rest of the leadership. Earlier this year, the rule was waived so the medal, the highest civilian honor given by Congress, could be awarded to civil rights activists who led the 1965 “Bloody Sunday” march in Selma, Ala. In years past, groups of World War II veterans such as the Tuskegee Airmen and the Navajo “code talkers” were awarded the medal.

It is unclear why it took so long for the waiver, known as a “suspension of the rules,” to be approved. The current iteration of the House bill was proposed in November 2015 by Rep. Robert E. Latta (R-Ohio). Latta had proposed a similar bill in 2013.

“Honoring veterans of the OSS with a Congressional Gold Medal will ensure that their heroic actions during one of our country’s most trying times will not be forgotten,” Latta said in a statement. “Their actions played an important role in winning the war and saved countless American lives in the process.”

Founded in 1942 and led by Gen. William Donovan, the “Glorious Amateurs,” as he called the OSS, were responsible for cloak-and-dagger operations throughout World War II, including sending operatives into Nazi Germany.

After the war, the OSS was dissolved, but in 1947 what remained of its infrastructure became the foundation for the CIA. Other branches of the OSS responsible for specific types of clandestine operations became early iterations of elite military units such as the Green Berets and Navy SEALs. The organization’s insignia — a spearhead — would also become synonymous with the Special Operations community.

“It is a great honor to see this important bill passed this year,” Dana Hudson, daughter of OSS veteran Capt. James W. Hudson Sr., said in a statement. “My father and his OSS colleagues put their lives on the line, often alone, in enemy territory for one purpose: to preserve the freedom of our nation and the world. I only wish he were here to receive this honor himself.”

The senior Hudson, whose wartime exploits include rescuing 13 U.S. nurses from behind enemy lines and arresting one of Nazi Germany’s most famous test pilots, died at 93 in 2011.