Born to Karl Friedrich Joachim and Johanna Elisabeth Christine (Dethloff) Levenhagen in the Village of Lübkow in the Grand Duchy of Mecklenburg-Schwerin on July 14, 1874. Baptized as Maria Wilhelmina Friederike Levenhagen at the Dorfkirche Lübkow on August 2, 1874. Confirmed at Lübkow on April 14, 1889. Emigrated from Hamburg aboard the SS Bohemia on September 13, 1889, arriving in New York on September 28.

Married Karl Heinrich Wilhelm Hannemann at St. Matthew's Lutheran Church, Chicago, on October 29, 1892. Together they had nine children:
1. Eduard Hermann Karl (b. 08/09/1893 in Chicago)
2. Lily Emma Wilhelmina (b. 04/19/1895 in Chicago)
3. Martha Louise Christine (b. 11/23/1896 in Chicago)
4. Albert Wilhelm Carl (b. 01/25/1899 in La Porte)
5. Meta Augusta Wilhelmina (b. 09/08/1901 in La Porte)
6. Walter Friedrich Carl (b. 01/29/1904 in La Porte)
7. Rudolph Ludwig Hermann (b. 03/01/1906 in La Porte)
8. Emma Anna Wilhelmina (b. 06/06/1907 in La Porte)
9. Herbert Ludwig Hermann (b. 11/05/1911 in La Porte)

She was a housewife who enjoyed gardening and ice cream. She mostly spoke German around the home and still corresponded to relatives in Germany throughout her life. She was a member of St. John's Lutheran Church in La Porte, and during a late life health crises experienced a spiritual revival that led her to become a fervent student of the Bible.

Died of myocarditis at home in La Porte on June 1, 1944. Buried in St. John's Lutheran Cemetery on June 4, 1944. Her son, Herbert, was serving overseas preparing to take part in the D-Day invasion two days later.

Obituary from the LaPorte Herald-Argus - June 2, 1944

Mrs. Mary L. Hannemann, 69, of 415 J. Street, died at her home at 10:15 o'clock yesterday morning following an illness of six months. The daughter of Mr. and Mrs. Carl Levenhagen, she was born in Germany on July 14, 1874, and came to this country at the age of 14 years, settling in Chicago. In 1900 she moved to LaPorte. On Oct. 29, 1892, in Chicago she was married to Charles H. Hannemann. Surviving are five sons, Edward C., Albert W., Walter F., Rudolph L., all of LaPorte, and Pfc. Herbert, overseas; three daughters, Mrs. Harry M. Porter, Wellsboro, Mrs. Paul E. Bates of New Carlisle and Mrs. Claude H. Moore of Waterloo, Ia.; eight grandchildren, three great-grandchildren; one sister, Mrs. Louise Koeppen of LaPorte, and one brother, August Levenhagen of LaPorte. Funeral services will be held Sunday afternoon at 2 o'clock at the Haverstock Chapel, with the Rev. Robert Sidebotham of Union Mills officiating. Burial will be in St. John's Lutheran Cemetery. Friends may call tomorrow noon until 11 A.M.Sunday at the home, and from noon Sunday until time of the funeral at the chapel.