The first Custom House built for the port of Buenos Aires was in 1603. The only work carried out in the harbour up to the end of the eighteenth century was the construction of thirty-five metres of brick quay-wall at the site of the "Arsenal" on the Riachuelo. We find that although between the years 1852 and 1858 many plans were presented for building of piers, these were only carried into practice and built by the Government under the technical direction of Engineer E. Taylor; a new Custom House replacing the fortress, a timber pier for loading and unloading goods, and another pier for passenger traffic at the locality of the old mole. In the year 1878 the Riachuelo was first opened for traffic for sea-going ships, and in 1879, 197 vessels with 55,091 tonnage had entered the Riachuelo. As early as 1862 Ed. Madero turned his attention to the question of docks for the port of Buenos Aires, and in 1865 applied for permission to construct them at his own cost, but the application was rejected. Four years later he presented another application, which suffered the same fate. In 1869 the total exports from Buenos Aires were 397,722 tons, the bulk of which were loaded at the Riachuelo, and steamers over 100 metres long frequented the harbour about the time of 1870. It was not until 1882 that Ed. Madero succeeded in obtaining the concession of building the docks for the port of Buenos Aires. The docks were to be constructed on the river side of the city, between the gasworks on the north and the Riachuelo River on the south.
The trade of the City of Buenos Aires up to the time of the opening of the South Basin had nearly all been carried on between the shore and the steamers by lighters and small steam tenders. The usual anchorage for the ocean steamers was in the "bar anchorage," a distance of about fourteen miles from the city. The cargoes were transhipped into lighters, which brought them as near to the shore as possible, and from this point they were taken to the Custom House in specially-constructed carts with very large wheels. Passengers were transhipped in the bar anchorage into small tenders, and were brought to a point about 500 metres from the end of the passenger mole. From these tenders, when there was sufficient water, they were taken ashore in small boats, while, if the water was too low to go alongside the mole, they also had to be brought ashore in carts. In many cases, however, passengers were brought on in tenders and landed at the Riachuelo wharves, which were then under construction. The first steamers that arrived in the River Plate were those of the Royal Mail Company, followed by the French Messageries Maritimes, and shortly afterwards by the Lamport & Holt Line.
Up to the year 1870 these lines, and a few more that were started, progressed very slowly, although the rates of freight were then very high; but after that trade increased gradually, and not only a fair number of sailing-vessels arrived yearly, but the regular lines of steamers increased their number of sailings. The great drawback was the deficient state of the port, where steamers had to lie at a distance of fourteen to sixteen miles, and most of the sailing-vessels at ten to twelve miles from the shore. There was no channel dredged, and even the Riachuelo was so scantily supplied with water that lighters drawing seven to eight feet were sometimes for weeks prevented from getting out to deliver their cargo to the sea-going vessels in the outer roads. The discharge was exclusively effected into lighters, which, apart from the heavy expense incurred by the receiver of the goods, presented the great objection that a considerable portion of the cargo was often broached and pilfered before it reached the shore, claims for which had to be paid by the ship. Another point was that many of these lighters were old sailing-vessels or steamers, and, in the unseaworthy and leaky state they were in, often arrived with their cargo considerably damaged. On the completion of the South Basin on 28th January, 1889, passengers were able to embark or disembark with a little more comfort, and cargoes were landed on the quays. Docks 1 and 2 have each a water area of 23 acres, being 570 metres long by 160 metres wide, with a quay length of 1,420 metres. No. 3 Dock has a water area of 27 acres, is 690 metres long by 160 metres wide, with a quay length of 1,660 metres. No. 4 Dock has a water area of 25 acres, is 630 metres long by 160 metres wide, with a quay length of 1,535 metres.
All these four docks, when they were originally finished, had a depth of 23 feet 9 inches below low water, so that, however low the river may be, there should never be less than 23 feet 9 inches in the docks. Since then dredging has been going on and the docks have been deepened to receive larger vessels. The docks are united by passages 20 metres in width, each passage being crossed by a swing bridge. Dock No. 4 is entered at its northern end by the north lock. This lock opens into the North Basin, which has a water area of 41 acres and a quay length of 1,409 metres and a depth of 21 feet 3 inches. The total area of the basins and the four docks is 174 acres, and the total length of quays 8,482 lineal metres. The following are the dates the various basins and docks were opened to traffic:—
| South Basin | 28th January, 1889 |
| South Lock, Dock No. 1 | 31st January, 1890 |
| Dock No. 2 | 26th September, 1890 |
| Dock No. 3 | 31st March, 1892 |
| Dock No. 4, North Lock, North Basin, and Graving Docks | 7th March, 1897 |
| First half of North Channel | 15th June, 1897 |
| Second half of North Channel, buoys and beacons | 31st March, 1898 |
The timber sea-wall was built to a level of 16 feet above low water, and the stone sea-wall to 19 feet. Originally there were built three sheds in the South Basin, three sheds and two warehouses in Dock No. 1, two warehouses and two sheds in Dock No. 2, five warehouses in Dock No. 3, and four warehouses in Dock No. 4, the total capacity of these sheds and warehouses being 525,510 cubic metres, and the floor area 192,800 square metres. Since then, several warehouses have been built, and some burnt down. The total cost of the harbour works as contracted for by Ed. Madero was $35,000,000 gold, or, say, about £7,000,000. This includes the South Basin, Dock No. 1, Dock No. 2, Dock No. 3, Dock No. 4, North Basin, North Channel, Graving Docks, machinery, etc.
The following statement shows the total tonnage that passed through the port of Buenos Aires in 1880, 1890, 1900, and 1909, and clearly shows the advance made in the last 30 years.
These figures include steamers and sailing-vessels, and local as well as foreign trade.
| 1880 | 644,750 tons |
| 1890 | 4,507,096 tons |
| 1900 | 8,047,010 tons |
| 1909 | 16,993,973 tons |
In 1909 we find that 2,008 steamers and 137 sailing-vessels entered the port of Buenos Aires from foreign shores with a tonnage of 5,193,542, and 1,978 steamers and 129 sailing-vessels left the port for foreign shores with a tonnage of 5,174,114; out of these, British boats lead with 2,242 steamers and 37 sailing-vessels, or, say, 53½ per cent, of the total.