Being thankful for God's grace through 125 years, Holy Cross held anniversary services on June 26, July 3 and July 10. Two services were held on July 10. Rev. Rohlfing was the preacher and celebrant at the 8:30am German service. Rev. Schmidt was the preacher at the 10:00am English service. On July 3, 1966, Rev. Dr. Ray F. Martens, professor at Concordia Seminary, Springfield, Illinois. He was the great grandson of Rev. J.G. Birkmann, pastor of Holy Cross (1850-1865).
The Lutheran Recreation Center, now known as Camp Wartburg, was developed in 1964.
1966 was the sesquicentennial year for Monroe County. A 150th Anniversary Plaque Dedication was conducted at the courthouse in Waterloo. Rev. Schmidt represented Holy Cross as one of the oldest churches still in existence and read a dedicatory prayer.
Rev. Schmidt accepted a call to Bethany Trinity Lutheran Church, Waynesboro, Virginia, in September 1966. He returned to preach at the 150th Anniversary service on July 7. 1991. Rev. Mark Herr of Holy Cross, Renault, served as the vacancy pastor.