Al Cassidy, a St. Paul candy salesman in the 1920s, played a sweet but little-known role in world history.

An Army motorcycle courier, Cassidy delivered the ultimatum papers demanding Germany's surrender that ended World War I on Nov. 11, 1918 — 100 years ago today.

Born in Philadelphia in 1883, Cassidy joined the Army in the early 1900s, was stationed at Fort Snelling by 1911 and became a captain and trusted confidential courier for Gen. John J. "Black Jack" Pershing — commander of U.S. forces on WWI's Western Front. Cassidy and Pershing first crossed paths along the Mexican border where the U.S. Army was chasing Mexican revolutionary Pancho Villa before the U.S. entered WWI in 1917.

"In all my time in the Army, General John J. Pershing was the only man to ask me if I was tired," Cassidy told the St. Paul Pioneer Press when Pershing died in 1948. "He was the greatest man in the world."

Cassidy was among only a handful of military personnel who carried a pass allowing him to go anywhere behind Allied lines during WWI — ultimately delivering armistice papers between the Allies' Supreme Commander, French Gen. Ferdinand Foch, and the Germans.

"He carried dispatches that changed battlefronts and affected the entire course of the World war — dispatches whose acquisition by the enemy would have meant disaster," the 1948 newspaper article said.

Cassidy didn't say much about his WWI days. So his role was largely forgotten as he settled in St. Paul, raising five kids with his wife, Marie — whom he met while playing baseball at Fort Snelling in 1912.

"He was a confidential courier," his son, Albert, recalled at age 97, "and he never spoke of his time in the military."

Enter great-granddaughter Megan Meuli, 45, of Richfield, a career counselor for women veterans in Hennepin County and a family history buff. She sifted through a lost box of letters and documents in 2015 after the death of her father, the courier's grandson Jim Cassidy. Meuli's mother, Nancy Cassidy, unearthed the missing box on the first Father's Day after Jim died.

"I cried," Meuli said. "It was a gift and we were absolutely amazed to find all these romantic letters written by a man who, according to family lore, was a bit of a curmudgeon." She has painstakingly organized, archived and transcribed the box's contents into a booklet for the family.

Here's an excerpt from a letter Al Cassidy sent to Marie — "My Own Darling Sweetheart" — on Mother's Day 1919:

"Honey dear what I wouldn't give to have you here with me today, to tell you how I love you, how I adore (you), how proud I am to be the husband of a woman who is so brave, so gallant, under the strain you have been under for the last three years. What I wouldn't give to have you on my knee, to hold you in my arms, to whisper words of love that you have missed for three long years."

Marie was home with their three older children in St. Paul — the letters first addressed to 1458 Charles St. and then 137 S. Cleveland Av.

"Tell the babies daddy loves them and will soon have them with him," he wrote on June 3, 1919. "Millions and millions of kisses and bushels of love."

Two more children joined the family after the war when Cassidy was honorably discharged from "meritorious service" in 1920. He actually mapped out his exit strategy in a letter to Marie written from France on Dec. 20, 1918 — a month after war's end.

"Honey dear … one thing is certain," he wrote, "I do not want to stay in the Army as being separated from you after this war is out of the question and if we are going to get anywhere in this world we must be together and I know how much I have lost by being away from you."

He only mentioned Pershing in one surviving letter, written eight months after the war from a Parisian hotel room. "I just finished putting up your picture and surrounding it. I have five pictures of General Pershing … so you see what wonderful company you are in," he told Marie.

Pershing and Cassidy sailed home together from Europe on the USS Leviathan in 1919.

Meuli said her great-grandfather reluctantly received a Purple Heart after suffering injuries during a WWI motorcycle accident. "He wasn't necessarily proud of the way he earned this medal because it was not gained during combat," she said.

He described himself as a "disabled veteran" in a 1942 WWII draft registration card when he was 58.

Cassidy was listed as a wholesale candy salesman in the 1930 Census, living on Ames Avenue on St. Paul's East Side. Meuli said he was still selling candy in 1941 at the State Fair in his late 50s.

He died in 1960 at 76 after skin cancer spread from around his eye. Marie died five years later. They are buried side-by-side at Fort Snelling National Cemetery, near where they met at that baseball game in 1912.

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com. His new book looks at 1918 Minnesota, when flu, war and fires converged: https://tinyurl.com/MN1918. Podcasts at www.onminnesotahistory.com.