One of the following source flags will be found on each project entry:

The original source of each project, the first clue here in the 21st century that it existed as an FBG project, is worth noting.

For the majority of the century of writings about Frank Gilbreth, Edna Yost's 1949 biography was the only source for FBG projects. She was selective in her inclusion and mention, focusing on projects that contributed to the later management/efficiency history and reducing most other mentions to one sentence or sometimes just the name of a city.

The three System books of 1908–09 each include many, many photos of FBG projects but, in oddly coy fashion, almost never identify them beyond a city or a project type (“large powerplant,” “reinforced concrete buildng in New York City” etc. Most of these are mentioned by Yost.

I have found no writings about the Gilbreths that include any other construction project beyond those noted by Yost.

None of the archives hold so much as a summary list of the projects. My working assumption is that the company records went to any successors, who may have been banks owed a default as the construction industry stalled repeatedly from 1907-1911, or were simply discarded by Frank at the time he changed careers, or were weeded by Lillian when she chose papers to donate to Purdue and elsewhere. In any case, Purdue holds next to nothing on the construction era except some photos later re-purposed in the management efforts.

The vast history of Frank Gilbreth's accomplishments as a builder was thus lost as the people who knew and remembered them passed away. Edna Yost's selective and brief list was all—or very nearly all—that remained until I began this project.

There are two categories for what I rediscovered: FBG jobs that were listed in some intermediate form, such as company ads throughout the active years, and ones for which no secondary record exists.

I take credit for rediscovering all projects that did not appear in a convenient summary such as an FBG ad or a trade magazine summary of jobs executed by FBG. These were found by locating one or more trade notices, sometimes as innocuous as a call for workers, and following the clues. I was sometimes lucky enough to find a trade journal or even newspaper article of considerable substance about the project, but these were not listed or referenced in any source that began with “Frank Gilbreth” as the management and engineering field has noted him.

I take partial credit for finding the original FBG ads and job summaries, and mentions in trade articles, that led to further discovery of the jobs they listed. These bold flags do connect “Gilbreth” and many of the projects, and have lain in the record for over a century, available to any researcher. To the best of my knowledge, no one after Yost's record has noted them.

I concede — and am grateful — that the mass digitization of materials as mundane as construction and engineering trade journals made it simple if tedious work to trawl again and again for clues, using chains of keywords and more and more educated guesses. I wish no more credit than for being the first to recognize that this information was at hand… and for spending considerable time and effort going after every last ‘fish’ I could trawl up.

In each case, the source listed in the head of a project is where I first found a reference to it. There may be earlier sources, but if (for example) I knew a project from the bounteous 1907 Sweet's advertisement, finding it in a 1905 job summary was secondary.

The original source for FBG projects is Edna Yost's 1949 dual biography Frank and Lillian Gilbreth: Partners for Life. Page numbers from the original hardcover edition are given. The limitation of Yost's work, and nearly all writing that has followed for seventy years, is that it focuses entirely on the period 1910–1925, with fairly boilerplate content on Frank and Lillian's lives leading up to both their marriage and their later partnership. If something did not contribute to understanding of the management and efficiency era, it was likely left aside or minimized.

The three books of 1908-09, Field System, Concrete System and Bricklaying System contain many job references that could have been used to find jobs not mentioned by Yost. I did not find them particularly useful until the end, when I could match Frank Gilbreth's carefully anonymized photos and comments to known projects.

Very early on in the research process, I found most of these valuable FBG ads or trade job summaries that provided most of the projects not mentioned by Yost. As I said, I take “half credit” for these jobs, since their existence should have been easy for anyone to find, even in the paper-archive days.

FBG Projects listed in the 2-page advertisement from the 1909 Sweet's Catalogue of Building Construction, which lists some 41 jobs by client name and city, some with job type. A number of these entries are unique and mentioned no where else in any primary FBG source. The projects are listed as examples of successful cost-plus-fixed-sum contract, and is neither exhaustive nor includes jobs done under other contract types. Since the catalogue was published in early January 1909 (as it was each year), and the ad lists the San Francisco office, which was closed in about October 1908, it can be assumed that all jobs on the list were completed or in progress at that time. The earliest jobs on the list that have been identified date to 1902.

Some of the jobs listed in this ad are peculiar to find there, such as Roper Hospital, which was then under legal challenge because it was most specifically not meant to be built under cost-plus, and the Bay Road Construction project, which was part of a famous civic/corporate financial meltdown with no results. Many other entries are oddly worded as well. It has every sign of being composed by someone in the company offices not entirely familiar with the projects it lists.

FBG projects listed in a massive 17-page ad that appeared in several journals in late 1907. The version from System: The Magazine of Business, November 1907 is used as the reference. It lists and shows photos of some 24 projects, many uniquely.

FBG projects listed in a long current-jobs notice in the 7 Jan 1905 issue of Engineering Record. It lists some 15 jobs, a number of which are unique references.

FBG projects listed in a 2-page ad from the 28 Dec 1905 Engineering News. None are unique but photos, cost details etc. are additional data.

FBG ad of four pages in Cement Age, October 1906, listing of subsidiary companies, primarily Underwriter's Engineering and Corrugated Concrete Pile Co, with mentions of four jobs, one of which is unique.

FBG ad of two pages with ten letters of recommendation, some of which represent unique jobs and all of which add details of time, place, cost and architect/engineer.

In searching over and over through the digitized archives, often using one or more keywords from the above sources or prior discoveries, I found job notices, calls for laborers, and both construction and customer-trade articles on Gilbreth projects. A date, a city, and sometimes a job location were enough to keep searching for more information. I am proud of the large number of “lost” FBG jobs I was able to discover using this basic process, and these entries are tagged as follows:

Sources located by the author in primary materials such as job notices, articles and other, non-FBG sources. Indicates primary and original research.

Sources located by the serendipity of being mentioned or referenced in material found as an original source (JDG-1). Noted separately simply for the pleasure such discoveries brought.

I was fortunate enough to be able to discard an interim UNK source flag for a few projects on which I had extensive notes, but had somehow misplaced the original provenance. All such were eventually rediscovered, except for one project currently assigned to the “Unverified” entry.