The modern-day Mr. Biddle made his living as an insurance broker, starting in 1940 with Biddle, Townsend & Co. He was named partner in 1955 and later became director of the renamed Biddle & Co. He retired in the 1980s from the Newtown Square firm.
Among the achievements important to him was his time on the Lower Merion Board of Commissioners, from 1964 to 1972, said his daughter Lydia Biddle Thomas.
"He thought it was important to give back to your community and improve where you live," his daughter said.
Mr. Biddle was on the board of directors of many civic organizations in the Philadelphia area, including the Philadelphia Zoo. But his most long-standing allegiance was to the Fort Mifflin Committee of the Military Order of Foreign Wars, which he joined in 1957 to save and restore the colonial-era military fort, then in poor condition.
He was drawn to the project because he "was a patriot, and history was a big interest of his," his daughter said.
On Mud Island in the Delaware River, the fort was the site of a furious British naval bombardment in the fall of 1777 as Gen. William Howe tried to get upriver to resupply his troops bivouacked in Philadelphia. Without supplies, Howe could not pursue and rout Gen. George Washington's ragtag army before winter.
An overmatched band of patriots, hunkered down in the wood-and-stone fort, withstood a hail of cannon fire for six weeks, stalling the British advance long enough for Washington's troops to settle into their winter quarters in Valley Forge.
Finally, on Nov. 15, overmatched and out of ammunition, 40 patriots set the fort ablaze before slipping away in darkness to Fort Mercer in New Jersey, leaving the American flag flying. Even the Redcoats noted their courage.
"The behavior of the enemy did them honor, nor did they quit the place 'till their defenses were ruined, and the works rendered to rubbish . . . when they could defend it no longer," a British officer wrote, according to the fort's website.
Mr. Biddle chaired a historical committee linked to the fort, and worked on Philadelphia's Fort Mifflin Advisory Committee. In 1986, he became the founding chairman of Fort Mifflin on the Delaware - a historic site now open to visits by tourists and schoolchildren - and he stayed involved until just before his death.
Mr. Biddle received many honors for his efforts on behalf of Fort Mifflin. On Oct. 9, 2003, Gov. Ed Rendell awarded him a commendation for his long history of volunteer service to the fort.
The same day, City Council President Anna C. Verna honored Mr. Biddle for raising more than $5 million for the fort's restoration.
Born in Jamestown, R.I., Mr. Biddle graduated from Episcopal Academy in 1936 and Princeton University in 1940, with a bachelor's degree in geology.
He served from 1940 to 1942 with the Army's 108 Field Artillery Battalion, 28th Infantry Division, and from 1942 to 1945 with the 909th Field Artillery Battalion, 84th Infantry Division.
During World War II, he was an artillery liaison officer with the rank of captain in the European Theater of Operations, and was awarded a theater ribbon with three battle stars for engaging in the Battles of the Rhine, the Ardennes (the Bulge), and Central Europe.
He also received the Bronze Star with oak leaf cluster for heroic action. After participation in the Army Reserve from 1946 to 1953, he was honorably discharged with the rank of major.
In private life, Mr. Biddle enjoyed piloting a private plane, aerial photography, golf, tennis, skiing, geology, performing magic tricks, and hunting. He also liked oil painting and woodworking.
He was married for 72 years to the former Mary Hopkins. The two met through mutual friends.
"They were truly devoted to each other," said his daughter. The couple lived in Penn Valley before moving in 1995 to Waverly Heights, a retirement community.
Surviving, in addition to his wife and daughter, are a son, Nicholas III; daughters Charlotte H. and Elaine Whitman; five grandchildren; four great-grandchildren; a brother; and a sister. A brother and sister died earlier.
A memorial service will be at 11 a.m. Saturday, May 11, at All Saints' Episcopal Church, 1325 Montgomery Ave., Wynnewood. Interment is private.
Donations may be made to Fort Mifflin on the Delaware, Fort Mifflin Road, Philadelphia 19153. To read more about Fort Mifflin's history, visit http://fortmifflin.us/about-the-fort/.
Condolences to the family may be offered at www.forever-care.com.
Contact Bonnie L. Cook
at 215-854-2611 or firstname.lastname@example.org.