The collection is arranged into 12 series:

Series I, Correspondence;

Series II, Diaries/Almanacs;

Series III, Account Books/Financial Papers;

Series IV, Pastoral Records;

Series V, Luther College Materials;

Series VI, Composition Books;

Series VII, Lists;

Series VIII, Programs;

Series IX, Newspaper Clippings;

Series X, Genealogical Records;

Series XI, Photographs;

Series XII, Realia.

The first series, Correspondence, comprises the great majority of the collection.  The series is arranged with Nils O. Brandt’s correspondence first, spanning 1850 to 1918 with some undated material.  Correspondence belonging to Realf O. Brandt follows, much of which was arranged in letter files, and covers the dates 1883 to 1922 as well as some without dates.  Realf O. Brandt’s letter files comprise a very large portion of the series, and occasionally also include some of his wife’s (Thalette Mathilde Galby Brandt) correspondence.  Thalette Mathilde Galby Brandt’s correspondence follows in the form of letter files, dating from 1908 to 1939.  Next is Olaf Johan Brandt’s correspondence from 1896 to 1908 and some undated material, followed by a small amount of Diderikke Ottesen Brandt’s correspondence.  Hers is from her husband Nils and her sister Thrine Ottesen, and spans 1880 to 1885 along with some undated material.  Olaf Elias Brandt’s correspondence from 1912 is the final part of the series, and is quite small.

Series II contains Diaries and Almanacs belonging to Nils O. Brandt and Thalette Mathilde Galby Brandt, with some that are unidentifiable.  Those belonging to Nils O. Brandt date from 1856 to 1913, including some without dates.  Thalette Mathilde Galby Brandt’s diaries and almanacs span 50 years from 1888 to 1938.  The unidentified diaries and almanacs date from 1851 to 1917.

The third series in the collection, Account Books and Financial Papers, begins with account books belonging to Nils O. Brandt dating from 1888 to 1906, some undated.  Realf O. Brandt’s account books span 1886 to 1923, including some books with no dates.  His financial papers date from 1913 and others are undated.  These include stenographer’s and reporter’s notebooks.  Thalette Mathilde Galby Brandt’s account books are from the years 1892 to 1903, along with undated books.  One account book belonging to Olaf Johan Brandt is also included in the series, dating from 1905.

Pastoral Records make up series IV.  The records are from Madison Lutheran Church located near Decorah, and date from 1872 to 1913 with much undated material.  This was one of Nils O. Brandt’s congregations, and the records in this series are his.

Series V includes Luther College Materials, from 1860 to 1866.  Subscription and pledge materials and a parochial report from 1860 comprise the series.

The Composition Books in series VI are not dated, but appear to have been used by Thalette Mathilde Galby Brandt to teach her son Olaf Johan Brandt.  The subjects include history and literature.

The seventh series, Lists, belong to Nils O. Brandt and Thalette Mathilde Galby Brandt.  Those belonging to Nils O. Brandt date from 1903 to 1917, with some undated material.  Thalette Mathilde Galby Brandt’s lists are from 1916.

In series VIII, Programs are found.  These date from 1889 to 1915, and include some without dates.  Many of the programs are from concerts, as well as other events, banquets, and celebrations.

Series IX includes Newspaper Clippings.  These belong to Nils O. Brandt and date from 1903, 1914, and some have no dates.

The Genealogical Records in series X include a draft of a biography of Nils O. Brandt written by his son Realf O. Brandt, handwritten information about Diderikke Margrethe Brandt Preus and her children, and a genealogical record sheet belonging to Emma Louise Brandt Naeseth dated 1928.  The rest of the materials in this series have no dates.

Photographs are found in series XI.  None of these are dated.  Photographs include individuals, groups, places, and stereoscopes.  Sizable portions of these are unidentified.  In addition, there is a partial box of cartes de viste belonging to the Brandt family.  Most of these picture friends of the Brandts and are unidentified.

Series XII contains Realia.