Once the insomnia and amnesia plague has been cured, Macondo begins to prosper. The town receives mail service, and there is traffic between Macondo and other parts of the country. Commerce begins, and Úrsula engages Pietro Crespi, an Italian pianola expert, to teach the girls Rebeca and Amaranta to dance. The Buendías begin to have bourgeois aspirations. Yet one notices, at the same time, that Macondo is a town without an economy; it is an agricultural community.
Like so many third-world countries, the town must purchase foreign, manufactured goods with its raw materials. Even experts like Pietro Crespi are foreigners, and so services, as well as products, must be imported. Macondo emerges, then, as a kind of metaphor for South America and its relations with such developed countries as the United States. There is a great desire for progress in Macondo, but there are only natural resources to pay for that demand. In the final analysis, the imported technology and manufactured goods that Úrsula's strangers bring are more expensive than the natural resources that the Macondians trade in exchange. Like the inventions that Melquíades introduces to the town, the fantastic technology of progress remains more curious than useful. And the knowledge to produce such wonderful things constantly eludes the Macondians themselves.
Macondo slowly moves out of its fantastic isolation. It slowly is invaded by foreigners — Yankees, government officials, Arab merchants, and brutal troops. In this report, Macondo may be regarded as a microcosm of South America's history. It is a fecund, yet a doomed Garden of Paradise, which loses its magical innocence to alien values, governmental idiocy, Yankee imperialism, inflated machismo, and human greed. Ultimately, Macondo is the apotheosis of the South American personality, the colonial child become liberated man.
For the most part, the subplots in this first section concern romance. Rebeca and Amaranta become obsessed with the Italian pianola expert. The unlikely romance between Aureliano and Remedios Moscote blossoms. Amaranta and Rebeca begin a violent rivalry for the affection of Pietro Crespi. These romances all have a comic touch to them. Out of despair, Amaranta mutilates her hand on a burning coal. Meanwhile, Pilar Ternera announces that she is pregnant with Aureliano's child. These developments all have a Rabelaisian color of hysterical comedy: love is interwoven with farce. All of the characters here are creatures of passion, and all seemingly lack a social conscience. On the other hand, sexual appetite seems all-important. Aureliano Buendía, for instance, has been carrying his desire for Pilar Ternera since infancy in the "inviolable backwater of his heart." Rebeca consoles herself over the loss of Pietro Crespi by eating handfuls of dirt, leaving "a harsh aftertaste in her mouth and a sediment of peace in her heart." This vital sensuality is aided by unusually brilliant images and a language that heightens our levels of awareness. At the end of Section 4, we see the demise of the patriarch. José Arcadio Buendía goes mad, haunted by the ghost of Prudencio Aguilar. This sets the stage for the emergence of the Colonel: José Arcadio I's son — Aureliano.