Thomas Robert Malthus may well have been the least favorite economist of Karl Marx. Basically Marx did not like him because he saw Malthus as blaming poverty on the poor themselves, their inevitable sinfulness that led them to constantly reproduce themselves excessively when things started to get better, thus leading to population pressing against the means of subsistence. Malthus recognized that people could act to reduce births even while still having sex, but as an Anglican priest, he considered such actions to be "vice," which he added to his list of war, famine, and pestilence as limits to population, with those being the first three of the Four Horses of the Apocalypse, the fourth being death.
However, in a more extended discussion of Malthus in the second volume of his Theories of Surplus Value, Marx also took Malthus to task both for making intellectual mistakes and for drawing on the work of earlier thinkers without properly crediting them. The main error was his formulation in the first two editions of his Essay on the Principle of Population, first edition published in 1798, of a "geometric" growth of human population supposedly conflicting with a supposedly "artithmetic" growth of food supplies. By the term "geometric" he meant exponential growth while by "arithmetic" he meant a linear growth process. The problem is that exponential or geometric growth is the general law of growth of all populations, including those entities that are the sources of food for humans. The supposed linear or arithmetic growth law is false. By his third edition Malthus corrected his error, falling back on Ricardo's law of diminishing returns in the face of limited land as the reason for why food supplies cannot grow exponentially.
Maex noted that the most important two people who preceded Malthus in formulating his atgument, with neither making the intellectual error Malthus made, were James Anderson, but before him Benjamin Franklin, who wrote the seminal essay Concerning the Increase of Mankind in 1751, although it would not be published until 1755 in England. Franklin was the first person to lay out the correct exponential law of population increase as a general law. It is a hard fact that Benjamin Franklin that was the first formal formulater of the Malthusian doctrine.
Franklin was the original Founding Father, indeed the only one of them internationally known prior to the American Revolution. He was most famous for his scientific study of electricity. But we know of him being an inventor of many things, both objects such as his stove as well as organizations such as postal service and lending libraries. He also invented the United States of America, at least as an idea. He did that with Albany Plan of Union he proposed in 1754, which became the basis for the original US government structure, the Articles of Confederation. He proposed it at the beginning of the French and Indian War at a conference with representatives of all the 13 colonies, but it was not accepted. Its inspiration came from Franklin's interactions with the confederacy of he upper New York State Iroquois Indian tribes, who banded together to support each other against the more numerous Algonkian tribes who surrounded them.
Unsurprisingly, Franklin's concerns about overly rapid population growth probably came from his own personal experience of being the 15th child born in a family that had 17 in all (from two wives for his father, Josiah Franklin). He was personally aware of how having too many children could put make it hard for a family to feed its children, not to mention drag down the general standard of living of a family.
Thus it is also not surprising that Franklin supported letting women choose to end pregnancies at their will. In 1748 he issued an American version of a longstanding English book, The Instructor, a book mostly devoted to mathematical instruction and other basic education. To it he added a medical pamphlet written in 1734 by John Tennent of Virginia. It included a set of detailed instructions of how to induce an abortion, with the suggested abortifacient being the plant angelica, long known to have this ability. It had long been used in Britain, where it was widely accepted as legal when used prior to the time of "quickening," when fetal movement begins, usually about 15 to 20 weeks into pregnancy. However, Franklin did not add any such rule forbidding its use to any period of time. The language in his work referred to the procedure as dealing with the "misfortune," that clearly an unwanted pregnancy. in his Autobiography to a Dutch widow who was able to continue to manage her business because of her "education" in these matters.
I close this by noting that the leaked draft of a possible SCOTUS ruling to undo Roe v. Wade written by Justice Alito contains a misleading characterization of the legal status of abortion in colonial period. He cites the work of earlyi 1700s legal theorist, Hale, who supposedly opposed abortion. But Hale only opposed it after the time of quickening, a point not noted by Alioto. This was indeed the British common law view of Britain at the time, and this was the general rule in the American colonies, although in fact they had no formal laws regarding abortion at all. The first of those in the US was not until 1821 in Concecticut, which in fact codified that old British rule, of only forbidding after the time of quickening. It would only be late in the 1800s that more severe laws came to be passed in the US forbidding abortion, something that almost certainly would not have been approved of by the primordial Malthusian ultimate Founding Father, Benjamin Franklin.