Heber J. Grant and his wife August act as proxies for the vicarious endowment of Warren G. Harding and his wife and for their proxy sealing. Although Apostle Wilford Woodruff was a proxy for the baptism of deceased U.S. presidents in 1877, Grant is apparently the first church president to act as a proxy for a deceased U.S. president. On 29 Sept. Grant and Apostle Reed Smoot are also proxies for the vicarious endowments of Ulysses S. Grant and Theodore Roosevelt.
[The Mormon Hierarchy - Extensions of Power by D. Michael Quinn, [New Mormon History database (http://bit.ly/NMHdatabase)]]