The Lincoln Highway bronze medallions for the concrete markers were manufactured by the Whitehead & Hoag Company of Newark, NJ. There are no known records of how the markers and medallions were designed, manufactured or the logistics of delivery around the country. The project was referenced in the minutes of the Lincoln Highway Association Directors meeting in late 1927. This was supposed to be a final and permanent marking of the Lincoln Highway, with the participation of the Boy Scouts. Markers were delivered around the country to be installed by the Boy Scouts on September 1, 1928. Some markers were saved for future road improvements, and/or erected later. Spares to replace damaged ones were also thought to be

available. The original Lincoln Highway Association's archives, as donated to the Transportation Section of the Special Collections Library at the University of  Michigan, contain a type written log of placement locations for 2,440 concrete markers and thousands of porcelain signs for this effort. Besides the Directors' minutes and this log there are no other official records regarding the markers except for a blueprint of a very rough sketch of the top of a marker. The markers were rumored to have been manufactured by a concrete manufacturer in Detroit.  The National Boy Scouts Archives were similarly bereft of any details of this magnificent project.

The Whitehead and Hoag company was a prominent maker of pinbacks, ribbons, banners, medals, tokens and medallions for souvenirs and other use. Here's some info from the Advertising Specialty Institute website,
http://www.asicentral.com/asp/open/aboutASI/promoindustry/history.asp
"Other Early Innovators
Developing an item carrying an advertising message was in no way the exclusive brainchild of Jasper Meek, although he's most often credited with founding the promotional products industry in America. The fact is, given a competitive commercial situation and a literate populace at any time in history, a specialty advertising item or two was probably devised by some enterprising merchant somewhere. For example, another firm that, like Geiger, started in Newark, NJ, was the Whitehead and Hoag Co., founded by Benjamin S. Whitehead. As a youth, Whitehead imprinted silk ribbon and button novelties for souvenirs and began experimenting with imprinting on thin sheets of a new material called celluloid. Whitehead went on to perfect the celluloid button, one of the best known and most widely used of all specialty advertising products. In 1891, his company was incorporated as Whitehead and Hoag. Hoag was Chester R. Hoag, a neighbor whom Whitehead had patronized for twine and other supplies. Also in Newark, the J. L. Sommer Manufacturing Co. began imprinting both sides of its stock buttonhooks and shoe horns in 1879."

And from VitualNewarkNJ.com:
http://www.virtualnewarknj.com/busind/misc/whitehead.htm

"Whitehead & Hoag, Sussex Avenue and First Street
From: Newark the Metropolis of New Jersey. At the Dawn of the 20th Century. 1901
The Whitehead & Hoag Company have utilized celluloid in its most attractive character, the advertising novelties produced by them in this material being by far more handsome and artistic than anything else which is offered in the line of personal advertising or appropriate souvenir work. This company was first organized under New Jersey laws in 1892 with a capital of $500,000. Its progress
has been so rapid that in 1899 the capital stock was increased to a million dollars, and the plant at Washington and Warren Streets, originally a three-story building 50 by 80 feet in floor dimensions, has been increased by the addition of a 50 by 100 feet four-story structure and another of like area and five stories in height. The aggregate of floor space is nearly one hundred thousand square feet, and there are several hundred persons employed by the company in the manufacture and sale of buttons, badges, banners, flags and an almost infinite variety of taking advertising novelties in celluloid, metal, ribbons, silk and woven fabrics. The plant, though only eight years in existence, is the largest of its kin in the world, and the goods it produces are sold all over the civilized globe. The main business office is in this city and at the works, but branch offices are maintained in no less than 30 leading cities, the one in London, England, being under the personal management of Mr. A. J. Keil, the secretary of the company. The other officers and directors are Newark's highly esteemed citizens. Mr. Benjamin S. Whitehead is the president and is a native of Newark and a graduate of her public schools. Mr. Chester R. Hoag, the vice-president, was born in Pennsylvania, but has been a citizen of Newark for many years. Mr. William A. Jones, the treasurer and counsel of the company, is a native of New York State. He is the active treasurer and legal adviser of the company."

There is also an extensive article about another Lincoln Medallion that Whitehead & Hoag produced for a National Lincoln Essay Contest:
http://www.historycooperative.org/journals/jala/24.2/hoffmann.html

I have the factory sample/specimen marker medallion that was allegedly acquired at an auction of the Whitehead & Hoag company in 1958 or 1959 when they ceased business. It was later acquired by collector Jerry Keyser in the late 1980s. I subsequently purchased this from Jerry about 5 or 6 years ago. I have not been able to locate the original purchaser. Additionally, I have not been able to locate any archives of the papers or corporate records of this company. I have contacted all the libraries, universities, and historical associations in the Newark area to no avail. It is thought that the papers would have correspondence with the company that manufactured the markers, and the Lincoln Highway Association. The unused medallion has three arrow shaped prongs that typically were broken off when pried out of a marker.  The manufacturer name of Whitehead & Hoag is present in the design on the inside of the medallion.

Howard Stovall, Lincoln Highway Association Attorney sends the following, "I did a NEXIS search on Whitehead & Hoag just for the sake of curiosity, and came up with the attached (mostly about the pin-back products). A 1985 NY Times article also mentioned a Newark Museum exhibit that featured some Whitehead & Hoag medallions":

From the Chicago Tribune - April 3, 1987 Friday, SPORTS FINAL EDITION
YOU CAN MAKE MORE THAN PIN MONEY WITH THE RIGHT BUTTON, by Anita Gold
Pinback buttons are fascinating to collect and study, for they offer an exciting education on past events, businesses, products, people, schools, fairs, transportation, organizations, causes and everything else from comic characters to cowboys.

Such buttons fall into countless categories, including sports, food, clothing, religion and theater.

If you're stuck on collecting pinback buttons, you'll find more than 5,000 examples pictured, described and priced in the "Price Guide To Collectible Pin--Back Buttons 1896--1986" by Ted Hake and Russ King. It is available in a 326--page hardcover edition for $45 postpaid from Hake's Americana & Collectibles Press, P.O. Box 1444, York, Pa. 17405. The book also lists button manufacturers and jobbers with dates when they were in business. It also gives examples of button manufacturers' advertisements.

The book includes a history of Whitehead & Hoag Co., which was the first button manufacturer and which remained the most notable and foremost throughout the early years of the industry. The names Benjamin S. Whitehead and Chester R. Hoag are synonymous with pinback buttons. Many old examples are paper--lined and have Whitehead & Hoag Co. printed on the back, along with one or more patent dates, referring to certain button patented features. Whitehead, who was born in 1858 in Newark, N.J., became a printer in 1870 and six years later exhibited samples of his work at the 1876 Centennial Exposition in Philadelphia. He traveled extensively both here and abroad, taking photographs and gathering ideas for novelties and buttons to be manufactured in his plant. Whitehead was a collector of fishing rods and reels and had more than 2,000 examples in his collection. Little did he realize back then that one day folks would get just as hooked on collecting Whitehead & Hoag buttons and novelties as he did on fishing gear.

Hoag, who had only a grammar school education, was born in 1860 in Wellsboro, Pa., and read every book he could get his hands on. He came to Newark in 1882 and worked for a paper and twine distributor for $8 a week. At the time, Whitehead was printing local picnic and party programs and did printing on silk badges and ribbons. One day, Hoag walked into Whitehead's shop to sell him some twine. The two became fast friends and formed a business that later was incorporated in 1892 and became the country's largest manufacturer of novelties and pinback buttons. A long, successful partnership continued until Hoag died in 1935 (Whitehead died in 1940).

The value of a pinback button----no matter the manufacturer----depends on its type, condition, desirability and authenticity, as there are many reproductions on the market. Many reproduced examples, however, are printed with modern company names, addresses and zip codes around the rim, which offers an instant clue as to the age.

Many examples are cleverly designed with colorful pictures relating to every subject imaginable. A late 1890s Whitehead & Hoag sample card said, "The Button is without question the best advertising Medium." Today pinback buttons are still manufactured by the millions.

Especially desirable and charming are character type buttons, which portray funny or famous folks. But different buttons portraying a certain character can have different values. For instance, buttons picturing Buster Brown and his dog that advertise Buster Brown shoes can be worth as much as $75 each, while other examples picturing the pair can be worth a fraction of that amount. Hake's book can help identify a button's value. The book has a corresponding price code for pictured buttons. They can range in value from $1 to more than $300 for a single button. There is also a code that tells you a button's approximate age as well as its original colors. Its extensive listing of manufacturers and jobbers is extremely helpful in determining dates when particular buttons and novelties were made.