Published Tuesday, 20 March 2012
Mr Mitchell chaired the painstaking peace talks which eventually led to the signing of the Good Friday Agreement in 1998.
His son Andrew, aged 14, joined members of his family at Parliament Buildings on Tuesday to watch the politicians at work.
Mr Mitchell told UTV: "Today is the day. I had a really wonderful experience with my son sitting up in the gallery at the Assembly listening to a debate that did not involve conflict or sectarian differences.
"It involved the ordinary issues of life in a democratic society."
The retired politician, who later acted as US Middle East envoy, has been on a tour of the region for the past three days.
One of the highlights, he said, was the black taxi tour which he took of the Falls Road and Shankill areas of west Belfast conducted by former prisoners now employed in the tourism industry.
He described this as "one small example of dramatic change."
However, Mr Mitchell said there was still work to be done in securing peace.
He explained: "I don't think any of us should exaggerate the realities. There are differences - there continue to be differences.
"The peace line still stands and I don't think genuine reconciliation - full reconciliation - will come immediately but perhaps over time with generational changes."
© UTV News