off, such obligations being usually wiped out in a foreclosure proceeding.
Closely allied with the telegraph service was the handling and dispatching of the United States mails. Previous to the coming of the South Side RR, the Long Island RR enjoyed a monopoly of the government contracts for transporting the mails on Long Island. When the South Side opened in 1867, it was to be expected that mail for the south side villages would fall to the new company. Somewhat surprisingly, this proved to be a slow process. The transfer appears to have been done piece-meal at first, at certain stations and not at others. For example, the mail at Amityville was changed over from the Long Island RR to the South Side on August 10, 1868. Not till July 1, 1869, however, was the mail for all the south side villages handed over to the South Side RR. Perhaps Oliver Charlick's potent political influence was effective in delaying the loss of the profitable mail contracts on his road.
In February 1870 the Postmaster-General further improved the speed of delivery of letters on Long Island by inaugurating a new mail route between Medford station on the Long Island RR and Patchogue on the South Side. Previously, all mail for the south shore villages originating at Long Island RR stations had been sent into New York and then transferred to the South Side. With the new service mail was transferred in mid-island the same day and delivered that much faster. Whatever further arrangements may have existed are not known today because of the paucity of our information.
The rolling stock of the South Side RR is rather well-known thanks to many scattered notices in the press of the day and the road's own reports to the State Engineer. In terms of mere numbers, this is the South Side's equipment broken down into types:
| Year | Engines | Passenger | Baggage | Freight |
| Coaches | ||||
| 1868 | 8 | 17 | 3 | 41 |
| 1869 | 11 | 21 | 5 | 75 |
| 1870 | 17 | 31 | 7 | 89 |
| 1871 | 18 | 35 | 7 | 89 |
| 1872 | 19 | 35 | 7 | 114 |
| 1873 | 20 | 50 | 5 | 117 |
