He was there in Denver, 1998, as then-First Minister David Trimble awaited the call from Oslo confirming that he and John Hume had won the Nobel Peace Prize.
As part of his role in drawing US investment, Bill Montgomery also chaperoned US President Bill Clinton and First Lady Hillary on their historic visit to Belfast in winter 1995 when they turned on the city's Christmas tree lights.
So as he retires from economic development agency Invest NI after 34 years, the father of three definitely has a tale or two. For the last three years or so, he's been director of Invest NI's advance manufacturing division, working with companies helping them grow jobs, exports and innovation.
"We have great NI companies competing regionally and globally in aerospace, materials handling, construction, auto, renewables, electronics and advanced materials and consumer products. They really are some of the best manufacturing and engineering companies in the whole of the British Isles."
He got his first job after university at a US insurance engineering company, assessing loss prevention measures at big companies like Apple and Pfizer. The job often took him to the Republic. "Ireland was booming with foreign investments as they had the big corporation tax advantage. I was visiting companies like Apple in the Republic and it occurred to me that I wasn't doing many visits in Northern Ireland - for obvious reasons, we weren't getting as much investment as we were still in The Troubles. I learnt about the Industrial Development Board (the precursor to Invest NI), then joined as part of an MBA programme."
He soon took on a challenging role in the US. "Firms were looking at Europe, the UK and Ireland - my job was to showcase that NI would be a good proposition. That was the summer of 1992 when my wife Alison and two young boys Michael and Matthew and I all went over and lived in LA."
The first big win was Seagate -the hard-drive manufacturer which now employs over 1,000 in Derry. But Mr Montgomery is quick to give credit to his predecessor. "Before I got there my colleague Grainne McVeigh had already done all the groundwork. They committed at the end of the year, and it was a big win - a hi-tech company with 350-person staff. At that point Ireland had been winning all the companies like Hewlett Packard. Intel had been another big win for them and they thought that they would get Seagate."
Another highlight was accompanying the Clintons on their visit to Belfast in the run-up to Christmas, 1995. He was in the company of the First Couple a number of times. "Bill did have an incredible energy about him. He has quite a huge personality, and I remember how he could talk to people as if he knew them - he just had a knack of latching on as if he knew them well."
Bill was asked to head up the North American headquarters of IDB in Chicago, this time with a third son, Ian, in tow. "At that time one of the sales team, Ian Murphy, had been courting and promoting NI to Allstate Insurance. We then managed to secure Allstate Insurance in October 1998. They committed to a couple of hundred people in IT, and there's now over 2,000. I was just a part of that.
"Allstate was announced as part of an 11-city roadshow tour with the Secretary of State Mo Mowlam and the First Minister David Trimble. When we were in Denver they announced that David Trimble and Deputy First Minister John Hume had won the Nobel Peace Prize. Word came through to him to expect a call from Oslo and people got quite excited about it, though Mr Trimble was really quite reserved."
The family returned home in 2003, and Bill then became director of Invest NI's international investment division. Jeremy Fitch, Invest NI's executive director of business solutions, paid tribute to Bill's work. "Bill has been one of the key leaders for inward investment into Northern Ireland over the last three decades and his contribution in this area has been immense. A significant proportion of Bill's career was spent in the US where he led the NI team and oversaw significant investments from Seagate and Allstate. More recently, when based back in Belfast, he has had strategic responsibility and led the inward investment focus on developing our legal services sector. He added: "A true team player, many of us have benefited from Bill's wisdom, experience and guidance."