McLane was instructed to inform the English that his appointment signaled a break from the John Quincy Adams administration, and that issues of dispute under the Adams Administration would no longer be issues in a Jackson administration. His main assignment was to open up trade between the United States and the British West Indies. In this effort he was well received by Lord Aberdeen, the Foreign Secretary, and successfully accomplished his mission. During his tenure, his personal secretary was Washington Irving, who was thereafter a close and loyal family friend.