COSCA was founded in July 1976 at the Grandfather Mountain Highland Games in North Carolina by the late Dr. Herbert MacNeal, under the tutelage of the late Ian Campbell, 12th Duke of Argyll. It was created to be a membership organization, intended to support Scottish clan and family organizations in the USA. COSCA welcomes all organizations and individuals to join us in our work to strengthen and energize the efforts of all Scottish heritage surname societies.

The organization was incorporated in the State of Delaware in 1976 as a not-for profit charitable and educational corporation. The IRS granted COSCA tax exempt status under section 501(c)(3) of the Internal Revenue Code and it was given Employer Identification Number 23-7430128   The dual mission of COSCA, as stated in its bylaws,  is to represent the interests of Scottish clan and family associations and other heritage member organizations from across the USA, and in the process promote our shared Scottish heritage and culture, through all forms of public education.

Each year, COSCA hosts a Clan & Family Caucus for its members at GMHG, to which visiting chiefs who are honored guests of those games are invited to attend and address us.  For the past 20+ years, COSCA has also co-sponsored the Annual Scottish North American Community Conference (SNACC), convened at different locations around the country. COSCA publishes a quarterly newsletter, The Claymore, which features clan-related news from Scotland as well as other items of general interest to the broader Scottish heritage community.

COSCA is governed by an elected twelve-member board of directors. Past presidents of COSCA include a number of very prominent and well-known individuals from the larger Scottish American community— including Bob McWilliam, who was invited to address the Scottish Parliament, Dr. Phil Smith, noted genealogist and tartans authority, Professor Christie Harrison from the University of Arizona, who expanded COSCA's membership westwards from its home base on the East Coast, and Bob Henderson, well-known author of a number of publications on Scottish septs and surnames.

COSCA also maintains an Advisory Board of prominent Scots and Scottish-Americans.  These include Scottish peers — Andrew Morrison, Viscount Dunrossil and Jamie, Lord Sempill, Clan Chiefs — Major Sir Malcolm MacGregor of MacGregor, Bt., late of Scots Guards, and Madam Pauline Hunter of Hunterston, former Congressman Mike McIntyre, founding Co-Chair of the Friends of Scotland Caucus in the Congress, and Stephen Quillin, President of the GMHG, among others.

COSCA has its owned registered tartan, created in 2000. It is based on the "red MacNeil" tartan, in honor of COSCA's founder, Dr. Herbert MacNeil. COSCA's logo was created by Past President Susan MacIntosh in 2012.