We can divide the development of the telegraph system into five phases, which you can observe as you scroll down.
In 1844, the federal government funded the first telegraph line in the United States to see whether Samuel Morse's telegraph invention worked. You will see this first line between Washington and Baltimore. The stations opened to the public the next year.
The experimental line worked, so in 1845 new telegraph companies built lines to connect the biggest cities in the Northeast. Watch these lines grow between 1845 and 1847. The biggest users of telegraphs were business people and newspapers, who clustered in big cities, so it made sense to build telegraphs to connect them.
The first telegraph connected New York to St. Louis, on the western border of the East, in 1847. The next few years saw lines push south to New Orleans (the biggest market for agricultural goods from the center of the country because products floated south on the Mississippi River) and north to Canada. Watch lines and offices grow denser in subsequent years.
The first telegraphs on the Pacific Coast connected gold mining towns in the Sierra Nevada to the market cities of Sacramento and San Francisco. Watch the first lines appear east of San Francisco.
In the late 1850s, companies in California and Missouri built lines toward each other along two routes. One, called the Central Route, crossed the waist of the country. The other, called the Southern Route, swung southward. You can see growth along both routes using the slider. For eighteen months, the Pony Express ferried telegrams between the Eastern and California systems. In 1861, a gigantic push from both sides completed the transcontinental telegraph system on the Central Route. The Southern Route effort was put aside until later.
Choose from the options below to use colors to highlight (a) the companies that built networks, (b) whether a line was part of a Pacific telegraph system (built by multiple companies), or (c) the whole American telegraph system (all networks in black).
Some features of the map are tied to dates, so they will change as you adjust the time slider. These features are telegraph networks (stations and lines), mail routes, Native American cessions and reservations, and historic states and territories.
To show a mail route, the time slider must be within the dates the route operated. For example, the Pony Express operated from April 1860 to October 1861. To see it, (a) position the time slider within that range and (b) check Pony Express (letters and telegrams) in the layer list in the lower right.
The cities shown on the Historic Cities basemap are the top 100 U.S. cities of the decade, according to the U.S. Census. The font size for these cities and towns correlates with their population. Major cities in Canada and other smaller cities that were important in the telegraph network are shown in italics.
Scroll through the time slider to examine how the network developed from one route between Washington, DC and Baltimore to a transcontinental route, and then click a station or line to get more information.
Additional layers will become available as you move the time slider and zoom in and out.
Explore the map using the following tools:
Please note that this map is a work in progress. It displays the data we have collected so far, but it is not a complete map of all telegraph stations and lines.
One of the biggest problems facing the United States in the nineteenth century was uniting a vast nation. In 1800, the country hugged the Atlantic coast. By 1900, the country stretched from the Atlantic Ocean to the Pacific Ocean. American leaders feared that new states on the Pacific Coast would feel so far from the rest of the nation that they would try to form an independent nation.
To solve this problem, Americans placed their faith in two new technologies: telegraphs and steam engines. But neither of these technologies united the nation overnight. It took decades to build telegraphs and railroads that stretched from ocean to ocean and united all the states.
To help us understand the process of uniting the states, we built the first digital map of a telegraph system. We invite you to use the map to see for yourself how modern technology helped build a transcontinental nation.
Start by scrolling down on the sidebar to view the five phases of telegraph development. Then, you can explore the map in more detail using the following tools:
We hope you enjoy the map.
This map is a work in progress. It displays the data we have collected so far, but it is not a complete map of all telegraph stations and lines.
How to Cite this Map:
Edmund Russell and Lauren Winkler, "Uniting the States with Telegraphs, 1844-1862," Carnegie Mellon Library, https://telegraph.library.cmu.edu/.
Edmund Russell is the David M. Roderick Professor of Technology and Social Change, and Professor of History, at Carnegie Mellon University. He is writing a history of the transcontinental telegraph. His email is email@example.com.
Lauren Winkler is a cartographer in Pittsburgh who specializes in bringing historical data to life using modern digital tools. Her website is https://skeetidot.github.io/.
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