Between 1970 and 1980 Sinkford held management positions in
marketing with
Gillette,
Avon Products,
Johnson Products, and
Revlon; he later founded his own business, Sinkford Restorations. Following the resignation of Morales in 2017, Sinkford was asked by the UUA Board to return as interim co-president for the roles of president as outlined in the UUA bylaws for the final three months of Morales's term. Sinkford shared the interim co-presidency with Rev. Sofía Betancourt of
Starr King School for the Ministry and Dr. Leon Spencer, professor emeritus in Leadership, Technology, and Human Development at
Georgia Southern University. Their interim co-presidency was a time of stabilization following the resignation of Morales and other key staff members at the UUA as well as the death of Moderator Jim Key, as well as discernment about the UUA's approach to racism and white supremacy. Sinkford's interim co-presidency ended with the election of Rev.
Susan Frederick-Gray at the 2017 General Assembly. In 2022, in recognition of a lifetime of service to the faith, Sinkford received at General Assembly 2022, to a standing ovation, the Award for Distinguished Service to the Cause of Unitarian Universalism, one of the most prestigious awards bestowed by the faith. ==Education==