In early 1632, William Harvey traveled with Adam Olearius to a village between Jena and Grantville. During the trip, the court doctor suffered symptoms of gout. While there, Harvey met nurses Anne Jefferson and Sharon Nichols. Harvey disagreed with women practicing medicine, and would have been quite content to stand by and allow Jefferson to be burned as a witch. However, she was ultimately spared by the timely intervention of Committees of Correspondence leader, Gretchen Richter. Despite what had happened, Anne showed her respects to Harvey for his role in medical history.
Harvey subsequently visited Grantville proper, and obtained copies of up-time medical references as well as some encyclopedia pages concerning the history of England and the fate of king Charles I. After returning to England, Harvey presented these documents to Charles I. In response to this, reinforced by similar documents provided by Cardinal Richelieu, Charles I arrested those who would have overthrown him in the OTL, and made Thomas Wentworth, the 1st Earl of Strafford his primary advisor.
Harvey would later relate his irksome experience in Grantville to his colleague Thomas Hobbes, who also journeyed to, and settled in, Grantville.
In 1633, a delegation from Grantville was imprisoned in the Tower of London. Nonetheless, as an outbreak of plague swept through London, the delegation shared their medical knowledge with the Tower's occupants. Wentworth consulted Harvey briefly, but ultimately approved this course of action. Harvey, who'd also learned about modern chemical and biological warfare while in Grantville, feared that up-timers would instead plot to poison England. He reconsidered this position after he learned that Michael Stearns, then President of the New United States, heavily disapproved of developing chemical and biological weapons.
Wentworth further convinced Harvey that the delegation wasn't bloodthirsty and heartless, reminding Harvey that there were also children living in the Tower. Wentworth further suggested that Harvey's view of American women (the delegation was led by Melissa Mailey) might also have been clouding Harvey's judgment. Wentworth allowed the Grantville delegation whatever they asked for in the way of resources and labor, and assigned Harvey to oversee the affair from the standpoint of the crown. However, unbeknown to Harvey, the delegation took advantage of this to freely move around the Tower, in the course of which they had smuggled a hand-held radio to an imprisoned Oliver Cromwell.