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FBI Case Files

  • Conflict:   World War I
  • Records:   2,313,321
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FBI Case Files

Overview Description

These case files cover important investigations by an agency of the US government later known as the FBI, called the Bureau of Investigation. They include tales of espionage during World War I, case files for German aliens who were politically suspect, records pertaining to Mexican neutrality, and reports dealing with alleged violations of Federal laws. Serious, as well as far-fetched accounts will give you a fresh insider's perspective to the history of this time period.

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Publication Title:
FBI Case Files
Content Source:
The National Archives logo The National Archives
Publication Number:
Published on Fold3:
Last Update:
April 3, 2010
NARA M1085. Before it was called the FBI, the Bureau of Investigation investigated real and perceived threats to the nation and its citizens.


Today, the FBI is famously known throughout the world as the chief investigative unit of the United States government. It operates as a division of the Department of Justice to "protect and defend the United States against terrorist and foreign intelligence threats, to uphold and enforce the criminal laws of the United States, and to provide leadership and criminal justice services to federal, state, municipal, and international agencies and partners."

When it was first conceived in 1908, the department had no name. It was referred to as a "special agent force" or a "corps of special agents." It was officially designated as the Bureau of Investigation (BOI) on March 16, 1909. Only later, in 1935, less than two years after the end of prohibition, did it become the Federal Bureau of Investigation, or FBI.

The case files in this publication group are from the early days of the Bureau of Investigation. They cover changes in interstate commerce and foreign affairs during the Progressive Era of President Theodore Roosevelt. When the United States entered World War I, agents investigated espionage, sabotage, and other threats to a nation in wartime. The 18th amendment instituted prohibition in 1920 and gangsterism and similar lawlessness occupied many of the Bureau's resources. J. Edgar Hoover started working at the BOI in 1917, was named assistant director in 1921, and began his 48-year career as director of the BOI and FBI in 1924.

Case files in the BOI series are divided into four distinct groups:

Bureau Section Files, 1920-21
These records consist of investigative reports and correspondence from other areas of the Department of Justice whose investigative functions were later absorbed by the BOI. Many are duplicated in Miscellaneous Files.

Mexican Files, 1909-21
These are records relating to Mexican neutrality violations. They are arranged numerically, with numbers beginning with #232-. They cover investigations of conditions on the Mexican border beginning in 1916, including investigations of people operating against US interests during the Mexican civil wars.

Miscellaneous Files, 1908-22
Files are arranged by file numbers, corresponding to dates on which investigations were initiated. They contain investigative reports, correspondence, and memos dealing with alleged violations of federal laws.

Old German Files, 1915-20
By far the largest group of files, these are investigative records relating to German aliens who were politically suspect before and during World War I, more specifically, in the period 1915-20. Case numbers for these files begin with #8000- and comprise nearly 400,000 records. Explore the case of German terrorist Werner Horne and view images from his file below.

Search for documents concerning newspaper magnate, William Randolph Hearst.

More information about the entire collection can be found in NARA's descriptive pamphlet M1085.

Old German Files, 1915-20

German Terrorist Transports Explosives and Blows up International Bridge
The case file of Werner Horne, #8000-229

The case file for Werner Horne begins with a letter, dated 27 January 1917, from San Antonio, Texas, asking for particulars of Mr. Horne's connection to the "blowing up of the International Bridge between U.S. & Canada."

Another document in the file, written by a physician, attests that Horne is "not mentally sound" and "has hallucinations." He asks to be called "Prince" and speaks of inheriting ten million dollars. Officials at the federal prison in which Horne was interned felt otherwise - that Horne was shrewd and quite sane.

Horne's file is filled with intriguing pieces of evidence and opinion received from civilians and officials. In fact, Horne was wanted by many on both sides of the U.S.-Canadian border, not only for blowing up the bridge, but also for transporting explosives on passenger trains in order to complete the task.

In his closing arguments in the case of Werner Horne (which begin with the image placed here), George W. Anderson, United States Attorney, states:

"The law which is now before you is a very simple statute, and very obviously a common sense statute, which provides, in effect, that explosives, such as are used to blow up bridges, and used to blow up stumps in large quantities in the northern part of Maine, shall not be carried in cars [railroad cars] carrying passengers, in which you and I and our wives and children may be traveling. That law is a common sense law." (page 12)

And, "... that this defendant took a suitcase full of dynamite from New York, came over on the night train in a passenger coach, along with other people ... went across Boston and took another like passenger train, with other people, with other innocent suitcases, and he went to Vanceboro [Maine]." (page 13)

The file is extensive and includes letters from Horne mentioning his cellmate as "a French Canadian and a good fellow," a note about his sister Mrs. Neumann, and, testimonies from others involved. In a memorandum to the file, dated 15 September 1918, signed simply as "Chief," the writer confesses to "a feeling of some sympathy for Horn. Had he surrendered immediately after he blew up the Bridge at Vanceboro I think he would have been executed."

Personal information about Horne is available in a report dated 13 December 1918, in which an agent secures a statement about "himself and his family." A review of the entire file gives the reader a glimpse into terrorist activity in the United States in the World War I era, and how it was handled by the U.S. and Canadian governments.

(Note that some documents in this section were filmed out of order by NARA. You may need to read every other page as you proceed through the file to keep the story straight.)

Directors of the Bureau of Investigation, 1908-1935

Stanley W. Finch, Chief Examiner, Jun. 24, 1908-Mar. 31, 1909

Stanely W. Finch, Director, Mar. 31, 1909-Apr. 29, 1912

A. Bruce Bielaski, Director, Apr. 30, 1912-Feb. 10, 1919

William J. Flynn, Director, Jul. 1, 1919-Aug. 21, 1921

William J. Burns, Director, Aug. 22, 1921-May 9, 1924

J. Edgar Hoover, Director, Dec. 10, 1924-Mar. 21, 1935

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Search or browse the Investigative Case Files of the Bureau of Investigation, 1908-1922 here.


Investigative Case Files of the Bureau of Investigation 1908-1922. Records of the Federal Bureau of Investigation, Record Group 65, Publication Number M1085; National Archives, Washington.