A large number of companies built railroad bridges. If a bridge company existed prior to 1900, you can be reasonably safe in assuming it built railroad bridges. Their business focus, however, does not make them "railroads".

If a bridge company included a variation of the word "railroad" in its name, I include it in my catalog. Remember that bridge companies facilitated railroading by crossing rivers. Bridge companies seldom moved traffic.

One estimate suggests over 76,000 railroad bridges of all sizes were built in the United States alone. There were at least another 20,000 similar structures built elsewhere in North America. Railroad companies built the vast majority of those bridges under their own corporate oversights. Independent or semi-independent bridge companies built many of the very largest bridges.

While possibly related to railroad companies, bridge companies were seperate corporations.

Collectors might wonder why some railroad companies created separate bridge companies that built, managed, and maintained bridges while other companies did not. They might also question why some bridge companies seem unattached to any single railroad company?

A few bridge companies served multiple unrelated railroad companies. Tolls for passage across those bridges created revenue that repaid bonds and paid dividends to stockholders.

Most incorporated bridge companies were formed to bridge rivers on the borders between two states or countries.

Many states required (and most still do) companies that operated within their borders to be officially incorporated in those states. Obviously, multi-state incorporations created multiple layers of government oversight. Heavy government intrusion often imposed barriers for profitable railroad operation.

By operating as separate companies, interstate bridge companies were able to comply with multi-state (or multi-country) regulations and taxes without creating obligations on parent companies. It seems obvious that in order to comply with state regulations, bridge companies would have needed to operate at "arm's-length", even if they were direct railroad company subsidiaries. That means that most bridge companies would have needed to install and maintain their own track and switches and maybe even switching equipment.

So should we consider bridge companies as "railroad" companies? Did bridge companies consider themselves to be railroad companies? Without extensive research, we will never know for sure.

For this project, I need a simple answer. My goal is to list certificates from railroad companies. It is my opinion that if railroad companies considered bridge companies as separate entities, then we should, too. As a rule, I do not include bridge companies in this catalog.

My rule is to list bridge companies only when they include a word similar to "railroad" in their names

There are exceptions, of course. A few years ago, I polled my main contributors and they told me they wanted a few bridge companies to remain in the catalog. For the time being, a few companies will remain. These are bridge companies that most auction catalogers customarily list among railroad company certificates. That makes these few companies easy to track. I reluctantly include these four companies by custom:

Dunleith & Dubuque Bridge Co Louisville Bridge Co Louisville & Jeffersonville Bridge Co St Louis Merchants Bridge Co

If I had my way, I would not include any bridge companies in the database unless they included a word similar to "railroad."

No separate catalog for bridge companies? For those who would argue that there is no separate catalog for bridge company certificates, I invite you to take the opportunity to start one for yourself.