Built for walkers, not wagons
A footbridge is a span meant for people on foot. It may be a few planks over a creek, a narrow timber walk in a park, or a steel crossing above a railway. Traffic stays off it. The word still shows its parts: foot plus bridge. That transparency is useful, and it can also hide how old the pairing is, because each half reached English on its own long before anyone wrote them as one noun.
The job of the word has barely shifted. A bridge lets you pass over water, a ditch, or some other gap. Putting foot in front tells you who may pass: walkers, not riders or carts. What has changed is the scenery under the boards. Medieval English needed a name for a small crossing on a path. Later English needed the same name for walks over canals, roads, and station tracks. New objects, old label.
First written down in Middle English
The origin of the word footbridge is native, not a borrowing from French or Latin. Dictionaries reconstruct a Middle English form fotbrigge, also written fot-brigge. Both pieces were already English. Foot had come down from Old English fot. Bridge had come down from Old English brycg, which in Middle English often appears as brigge, brugge, or bregge.
Sources do not agree on the earliest date. Several general dictionaries place the first record in the later fourteenth century, in a band they give as 1325 to 1375. The Oxford English Dictionary, working from a named text, puts its earliest evidence around 1400 in the Canticum Creatione, a Middle English poem on the creation. That work survives in a manuscript of about 1400 and is often dated, as a composition, to about 1375. Another etymological survey, using a later hyphenated spelling, dates foot-bridge only to about 1500. The spread is typical of a common compound. Once both nouns existed, speakers could join them at any time; the date we print is the date of the oldest citation a lexicographer happened to catch.
What is not in dispute is the period. The compound belongs to Middle English. The sources used here do not show a clear Old English fotbrycg, so it is safer to treat the pairing as an English formation of the later medieval centuries rather than as a word already fixed before the Conquest.
Two inherited pieces
Foot is one of the most stable words in the Germanic family. Old English fot comes from Proto-West Germanic and Proto-Germanic forms that go back to the Indo-European root also seen in Latin pes and Greek pous. Close cousins remain easy to recognize: Dutch voet, German Fuß, Swedish fot, Gothic fotus. The English plural feet still shows the old fronting of the vowel that Germanic languages used in certain inflected forms.
Bridge has a different history, still Germanic, but tied to timber rather than to the body. Old English brycg comes from Proto-Germanic brugjo. Related words include Dutch brug, German Brücke, and West Frisian brêge. Behind the root, scholars often reconstruct an older sense of wooden flooring or decking: a beam or log laid down so that people could cross. That physical picture fits a small pedestrian span better than it fits a later stone viaduct, even though the simple word bridge came to cover both.
The compound is a straightforward determinative. The first noun names the users or the manner of crossing; the second names the structure. It does not mean a bridge made of feet. Middle English even had a lookalike running the other way. Among compounds of brigge, brigge fot meant the head or entrance of a bridge, the foot of the span as a place, not a walkway reserved for pedestrians. English kept both patterns. Only one of them became the ordinary name for a crossing that carts were not meant to use.
A sense that almost did not drift
Unlike many old compounds, this one did not collect a trail of obsolete meanings. In the Middle English record it already named a bridge for travelers on foot, and that is still what it names. The change is in the landscape around it. Early uses sit among streams and footpaths. Later centuries kept the same label for crossings over canals, then over railways and urban roads. A station walkway and a motorway overwalk are new objects under an old heading.
Spelling followed the usual path of English compounds. Early forms keep Middle English fot and brigge. Later print often hyphenates foot-bridge. Modern dictionaries treat the solid spelling as the ordinary noun. None of those graphic choices changes the analysis: two native roots, joined in English, still readable as such.
Parallel names, not one inherited compound
Other Germanic languages built the same idea independently rather than inheriting a single ancestral compound. German has Fußgängerbrücke, Dutch voetgangersbrug, Swedish gångbro, Danish gangbro. They are family resemblances, not proof that Proto-Germanic already possessed a fixed word for a pedestrian span. English happened to use the body-part foot as the specifier. Some of its cousins use a word for walking or going instead.
That is the useful residue of the history. The word looks obvious because it is obvious, and it is old because English did not wait for a borrowed term. If you want a date rather than a slogan, keep the disagreement in view: a Middle English fotbrigge by the later 1300s, an Oxford citation around 1400 in the Canticum Creatione, and a hyphenated foot-bridge still treated as new in some accounts around 1500. The boards underfoot changed. The name of the crossing did not need to.