The name Stevenson and its derivatives are a Scottish and northern English (Northumberland) patronymic from the personal name Steven. It was introduced to Britain as early as the 11th century. By 1150 the clan had moved north to Scotland in the parish of Newlands in Peebles part of the Strathclyde and the Border regions. It is here the Stevene Stevenson swore and oath of allegiance to England's King Edward I during England's brief conquest of Scotland in 1296. There is reference to this in the Ragman Rolls.
As a widespread family, unlike the clans who settled in one area it may have been ignored as a clan. It also never had a clan chief or followed the framework of typical Scottish clans. It did however have a tartan. It can be confidently assumed that Scotsmen with the name of Stevenson fought at the Battle of Bannockburn or at Culloden alongside well known clans.
As of 1999, the name Stevenson/Stephenson had been added to the Sept list of the MacTavish Clan. This would indicate the family was a valued friend or was connected through a marriage.
Some of the Stevensons resided near the borders between England and Scotland and as with other border clans were relocated to Ireland. They became known as Ulster Scots. My Stevenson Family could have been one of these clans or simply from Paisley, Renfrewshire, Scotland.