Niagara Falls Suspension Bridge

The bridge was built for the railroad and commerce between Canada and the U.S. A temporary bridge went up in 1848 then the completed bridge in 1855. However it wasn't limited to trains, a toll was established for horse & carriage and carriage passengers. In 1860 daily trains crossed the bridge. It was closed in 1897 and dismantled. An interesting tidbit was that the cables were found to not have deteriorate of the course of 50 years of use.
Houghtaling's Handbook of Useful Information ©1884 has this to say:
Railway Suspension Bridge, Niagara Falls.
Engineer. John A. Roebling. Height of towers on American side, 88 feet. Height of towers on Canada side, 78 feet. Length of bridge, 800 feet. Width of bridge, 24 feet. Height Lbove the river, 250 feet. Number of cables, 4. Diameter of cables, 10 inches, containing about 4,000 miles of wire. Ultimate capacity of the 4 cables, 12,400 tons. Total weight of bridge, 800 tons. Distance between railway track and carriage road below, 28 feet. Cost of construction, 500.000 dollars. Bridge first opened for railway traffic, March 8, 1855. Estimated depth of water in the channel beneath the bridge, 250 feet. Velocity of current,30 miles per hour. Velocity of Whirlpool Rapids,27 miles per hour Quantity of water passing through the gorge per minute, 1,500,000,000 cubic feet.

In Burke's descriptive guide for Niagara ©1850 we find even more tidbits about the bridge and it's original construction.

THE SUSPENSION BRIDGE?
This truly fairy-like work was commenced in February, 1849, under the suprintendence of Charles Ellet, Jr., Esq., of Philadelphia, an Engineer of good previous reputation, and who, in this work, added much to his fame.
The bridge was contracted to be built for the " Niagara Falls Suspension Bridge Company," on the Canada side, and " The Niagara Falls International Bridge Company," on the American side conjointly ; a bill for the purpose being passed by the Legislature of each country.
The manner in which the first line of connection was formed, was at once simple, yet ingenious. A kite was procured, to the tail of which was a string, and by flying this on the one side, and letting it out until it was over the other side, the gorge was spanned by the string, by which a cord was drawn Awful catastrophe.
across, and by means of this cord, a rope of sufficient strength to draw a cable, which latter, being well secured on both sides, was the means of transit for the first wire-cable of 36 strands, No. 10 wire, which was 1160 feet in length. Towers had now been erected on each bank, 800 feet apart, by which this wire-cable was secured, and on the 13th of March, just one month from the commencement, Mr. Ellet crossed in an iron basket, suspended from the cable. This conveyance was used constantly by the workmen in constructing the bridge. And even many persons paid for the novelty of a trip across in this frail track.
A foot-bridge, three feet in width, was soon constructed, and over this a great number of persons passed, each paying 25 cents to the contractor. A similar foot-bridge was now formed parallel to this, and the basket-cable in the middle.
A terrific scene occurred just about this time. Whilst the workmen were busy at the second footbridge, which was constructed about 250 feet from the American side, and about 150 from the British, a tornado from the s. w., struck it, turning it quite over. Six men were at work upon the flooring of the bridge at this awful moment, two of whom in a most unaccountable manner made their way to the shore upon fragments of boards. The unfinished structure was torn and wafted backwards and forwards like the broken web of a spider, and four helpless human beings, 200 feet from the shore, supported by two strands of No. 10 wire, were in constant expectation of a headlong fall and plunge into the rapids below ! Oh, who can fathom those men's thoughts just then ? But the tiny thread which held them to existence, proved strong enough to outlast the gale. On the first cessation of the tornado's force, a brave fellow-workman manned the iron basket, and with a ladder proceeded amid the pelting of the furious rain to save the sufferers. He reached the wreck ; he placed his ladder in communication with it, and the basket thus affording a means by which all were brought back safe to terra-firma, uninjured in person, but well nigh scared to death.
On the 26th of July following, Mr. Ellet drove a span of horses and a heavy carriage over and back, accompanied by his lady.
A disagreement, which had for some time existed between the directors and Mr. Ellet, now came to an open rupture, and the work was discontinued for some time.
The bridge, which we see, is not the structure Height of the Bridge.
originally intended. This being merely preparatory to the great structure, which was to have been suspended from stone towers, 70 feet high, and which would have been 10 feet higher than the present bridge, and wholly independent of it
The present bridge was at first economically formed of very slight materials, it not being expected to last longer than, until the great bridge was constructed, about a year and a half. It has, however, been strengthened materially, and is now capable of sustaining 250 tons, and is in use as a thoroughfare, unshaken by the greatest pressure.
The floor of the bridge is 230 feet above the river, and the depth of the river immediately under the bridge is 250 feet