But these forebodings were far from ever being realized. Indeed, even before the end of the year the conjunction of two causes produced a great demand for slaves and they were soon higher in price than they had been for years. First, planters from the cotton-growing States visited Virginia in great numbers in order to make purchases of slaves, doubtless, thinking they could buy cheaply, as it seemed that on account of the Southampton Insurrection Virginia was determined to get rid of her slaves at all hazards.[141] Second, the most important was the advance in price of cotton. This began, also, in 1832. It continued to rise for several years and by 1836 it had doubled in price,[142] while by 1839 its production, also, had nearly doubled. This increase was due almost wholly to the South and Southwest, Mississippi alone producing nearly one-fourth of the entire crop.[143] As a consequence we should expect to note a corresponding briskness in the slave trade. Such, indeed, was the case. We have no reason to think that more slaves were ever exported to the South from the Northern slave States during any equal period of time than there were from 1832 to 1836 inclusive. Of these 1836 is easily the banner year. In 1832 it was estimated by Prof. Dew that Virginia annually exported for sale to other States 6,000 slaves.[144] During the thirties, or even before the slave trade was carried on between the selling and buying States with about the same regularity as the exchanges of cotton, flour, sugar and rice.[145] Vessels engaged in the business advertised their accommodations. One trader, John Armfield, had three which were scheduled to leave Alexandria for New Orleans, alternately, the first and fifteenth of each month during the shipping season.[146] That the trade had become extensive is evidenced by the newspapers. Up to 1820 it was very uncommon to find a trader's advertisement in a newspaper, but even before 1830 such advertisements had become very plentiful. One could hardly pick up a paper published in the selling States, especially those of the Eastern Shore of Maryland and Eastern Virginia, without finding one or more. These advertisements often continued from month to month and from year to year.[147] An example or two may be interesting: "Cash for Negroes:--I wish to purchase 600 or 700 negroes for the New Orleans market, and will give more than any purchaser that is now or hereafter may come into the market." Richard C. Woolfolk.[148] "Cash for Negroes:--We will give cash for 200 negroes between the ages of 15 and 25 years old of both sexes. Those having that kind of property for sale will find it to their interest to give us a call." Finnall and Freeman.[149]