In 1609 it was bought by Sir Thomas Boyd and soon after sold again to Sir William Cunninghame of Cunninghamhead. Thirty years later the castle and the nearby lands were bought by Sir Robert Cunninghame of Auchenharvie. In 1655 Kerelaw Castle was purchased by Alexander Hamilton (the grandfather of Alexander Hamilton, a founding father of the United States of America), formerly of Cambuskeith (now known as 'The Mount'), and afterwards of Grange, who changed the name of the castle and its grounds to Grange, after the family home in Kilmarnock. Clements, Graham and McLatchie give the date of 1685 for the sale of Kerila (Kerelaw) to John Hamilton by Robert Reid Cunninghame of Seabank House (Auchenharvie) whose mining activities were causing him financial difficulties. The castle became the residence of the Hamilton family until 1787 when another Alexander Hamilton (second cousin of the American politician), built Kerelaw (or Grange) House nearby, with the castle quickly becoming disused.