Frederick was the 5th of 14 children born to German immigrant parents Fred Endorf and Caroline Heidemann. He married Lena Schafer in 1904; see her memorial for more information.

This was his obituary, published 21 Sep 1967 in "The Campbell News" of Campbell, Nebraska, page 1:

Services Held Saturday
For Fred W. Endorf, 89
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Fred William Endorf was born at Tobias, Nebraska, April 30, 1878 and was baptized May 18 at Zion Lutheran Church, Tobias.
After his elementary education in Zion Lutheran Parochial School at Tobias, he was confirmed and later he attended the Lutheran Academy at Milwaukee, Wisconsin, followed by a course at the Business College in Burlington, Iowa. His business career began with a furniture firm in Burlington, followed by a partnership in Wilcox, Nebraska, management of the Peoples Department Store in Campbell, and finally his own Store, which was long a landmark on the main street of Campbell.
He married Helena Schafer, October 13, 1904. They were blessed with nine children. He was active in church and civic affairs. In addition to regular attendance at Trinity Lutheran Church, Campbell, he also served as chairman and treasurer of the congregation for many years. He was elected to both the school and town boards of Campbell and served as mayor for several years.
Death came September 13, 1967. He reached the age of 89 years, 4 months and 14 days. He leaves to mourn his passing his wife Helena, eight children, Helen, Lydia, Frederic, Gertrude, Henry, Reuben, Maxene and Baxbara. One daughter, Caroline, preceded him in death. He also leaves to mourn his death one brother, Ernest, two sisters, Dora and Amalia, also many grandchildren and relatives and friends.

I know of a sleep in Jesus name
A rest from all toil and sorrow
Earth folds in her arms my weary frame
And shelters it till the morrow
My soul is at home- with God in heaven
Her sorrows are past and over.
I know of a morning bright and fair
When tidings of Joy shall wake us,
When songs from on high shall fill the air
And God to His glory take us
When Jesus shall bid us rise from sleep---
How joyous that hour of waking!

Funeral services were held Saturday, September 16 at 2 p. m. in Trinity Lutheran Church at Campbell with the Rev. Henry Pralle officiating. Music was by Mrs. Lyle Niemeyer, soloist and Mr. Winterstein, organist.
Interment was in Trinity Lutheran Cemetery. Fall bearers were Cecil Goiter, Gerald Bartels, Marvin Bartels, George Zuellner, Gus Kuhlman and Sylvester Meyer. Arrangements by Campbell Funeral Home.

CARD OF THANKS
Our heartfelt thanks to all who extended comforting sympathy and help in our recent sorrow. For the beautiful service, floral and memorial gifts and food; to Rev. Pralle for his comforting words. We are deeply grateful.
Mrs. Fred Endorf
and Children.