Holy Cross' ninth pastor was Rev. Ernst Schuessler. He started his ministry here in August 1910.

Mr. Theodore Scheiwe served as a teacher for the school from 1912-1917. During his tenure, he married a member of the congregation, Miss Clara Schmidt.

The wooden tower of 1874 was dismantled in 1913 to be replaced by the current stone tower. A new bell was also installed. Both the tower and bell were dedicated on November 9, 1913. The inscription on the bell (translated from German) reads: "The name of the Lord is a strong Tower: the righteous runneth unto it, and is safe. Proverbs 18:10. All Glory Be to God on High. Congregation at Wartburg, Illinois, 1913."

World War I started in 1914 in Europe. The United States joined the war in 1917. Several young men from Holy Cross served their country: William Boehne, Edward Buettner, Henry Hohnbaum, Theodore Hohnbaum, Oscar Schmidt, Alfred F. Boedecker, Walter L. Hoffman and Henry C. Kohlmeier.

The congregation's first constitution, dated March 1, 1849, authorized Catechismusexamina for instruction of confirmed members. The name used later was Christenlehre (Christian teaching). The minutes of meetings from 1882 showed that Rev. Nachtigall wanted a record of attendance to be kept so he knew who wasn't attending. As of 1900, attendance was mandatory for everyone until the age of 18. This teaching included a review along with a question-and-answer period which immediately followed the sermon. This practice continued until 1912 or 1913.

October 1917 brought the resignation of Rev. Schuessler. During the vacancy, several students from Concordia Seminary, St. Louis served the congregation.

Rev. William Moeller came to the congregation in March 1918. He was forced to resign, however, in April 1920 due to health reasons.

The parochial school's only time of inactivity was 1916-1918, after Teacher Scheiwe left. The children attended either Rock House School or Baum's School. The rural public schools were closed and reorganized into the Waterloo School System in 1950-51. During Rev. Moeller's pastorate, he relied heavily on his wife for the children's instruction.