"When the news arrived of the discovery of gold at Sutter's Mill, there was a big rush to reach California. At the time of Marshall's discovery, the state's non-Indian population numbered about 14,000. By the end of 1849, it had risen to nearly 100,000, and it continued to swell to some 250,000 by 1852.

The Western man, by braving the dangers of the overland route, might expect, if the Indians allowed him to pass unmolested, and he had sufficient stamina to endure the privations of the route over the Rocky Mountains and the passes of the Sierras, to reach California some time within a year. Many new routes were opened into California as a result of the Gold Rush. With an estimated 140,000 emigrants arriving in California via the California Trail between 1849 and 1854, routes were continually modified, tested or even abandoned.

His Eastern brother preferred the route by sea, via Cape Horn. There was a great development of the shipping industry after the discovery of gold in California. The sailing vessel was almost the only means of transportation. The voyage generally occupied about six months, which might be extended indefinitely should an accident to the vessel necessitate a visit to Rio Janeiro, Valparaiso, or Callao, while on route, for repairs, water, or provisions. Companies were formed, and vessels were bought and chartered. The between decks were fitted up with berths for sleeping quarters and the hold was reserved for water and provisions, any spare room being utilized for such freight as the passengers were able to ship and of the character likely to be most needed on arrival in California, generally provisions, household effects, lumber, and other building material.

Urged on by that pioneering spirit which seemed inherent in the blood of the American, and invited by the prolific soil and genial climate of these distant possessions, and a prospect of a new and enlarged field for commercial pursuits, large numbers of people migrated thither around Cape Horn. In spite of all of these difficulties, it has been estimated that as many as 25,000 persons made the sea journey to California in the aftermath of the gold discovery, or about as many as lived in the whole territory before 1848. These numbers were dwarfed by those who opted for travel by land. The round voyage to and from San Francisco would occupy about a year, but the larger part of the vessels that went to San Francisco in the first year of the gold excitement never returned. On their arrival there the officers and crews generally deserted the ships and started for the mines. As no sailors were to be had, the ship had to lie in the harbor uncared for and often without the services of a shipkeeper, and many of them were used as a foundation on which the present city of San Francisco was laid. Using a good ship as a foundation for a city appears rather odd, but here there has been seen an old condemned canal-boat or barge used for a bulkhead, and, with the help of dirt filling, making a fair appearance. In San Francisco many craft belonging to the companies who had no use for the vessels after they had landed their passengers and their belongings safely were hauled as far on shore as was possible, and after their usefulness for places of residence was ended, they were still further removed from tidewater by the filling in all around them, and there some of their bones remained.

The clipper ship, Andrew Jackson, Capt. Williams, from New York, arrived in San Francisco the afternoon of 25 March 1860 in the unprecedented time of 89 days and 7 hours, beating the quickest voyage of the clipper ship Flying Cloud. The Andrew Jackson was not an extreme clipper, having been built with a view for carrying as well as sailing. The clipper ship Flying Cloud, under command of Capt. Josiah P. Creesey, had made the shortest passages made under sail to San Francisco - one in 89 days and 13 hours in 1851, and a second voyage in a few hours more. The shortest homeward passage was made by the Northern Light in 79 days and a few hours to Boston.

It must be conceded that any vessel, however fast, must be highly favored by winds and weather to be able to cover nearly 16,000 miles in so short a time. There were a number of short passages made to San Francisco other than the phenomenal ones of the Flying Cloud and Andrew Jackson. One hundred and twenty days might fairly be considered the average. But the Westward Ho, Comet, Surprise, Swordfish, Young America, Firelight, Reporter, and others made the voyage inside of 100 days. The long passages were made by vessels leaving here in midsummer; the short ones were almost invariably by ships leaving New-York between Nov. 30 and March 1. There were, of course, many long and tedious voyages, when the elements conspired against all progress, where the ship could not get past Cape St. Roque and would be compelled to go back to the equator and try it again. Light winds, no trades where trades ought to be, calms, and counter currents often added many days to the passage of some of the fastest ships, to the untold anxiety of shippers and owners, and occasionally to the great worriment of the underwriters.

Sailing ships traditionally favored the Cape Horn route between the Atlantic and Pacific oceans, although rounding the cape by sail was hazardous. The strong currents and unpredictable winds in the Strait of Magellan were a considerable object to sailing ships, frequently more so than the storms and unfavorable winds of rounding Cape Horn. Steam navigation through the Strait of Magellan began in 1840. Under the Treaty of 1881 between Argentina and Chile delimiting Tierra del Fuego and the Straits of Magellan "Magellan's Straits are neutralized forever, and free navigation is guaranteed to the flags of all nations. To insure this liberty and neutrality no fortifications or military defenses shall be erected that could interfere with this object." Should some future conflict interrupt passage through the Panama Canal, maritime traffic between Atlantic and Pacific would again seek the old established routes around Cape Horn, through the Beagle Channel or via the Straits of Magellan. ..."

From http://www.globalsecurity.org/military/facility/panama-canal-horn.htm