Most of the information on the Anne Rutledge relationship was gathered by (Lincoln’s law partner) William Herndon in interviews with Salem residents after Lincoln’s death. Herndon wasn’t prone to romanticism, though his collaborator in compiling the info was a bit more inclined.
IMO, the Rutledge relationship grew into a great romance over the years largely because biographers decided there needed to be a great romance there. She was probably more of a crush as Lincoln had rarely encountered young ladies before (his mother died when he was a child, his sister when he was a few years older, his stepmother and stepsisters were basically hillbillies) and she was probably cute and flirtatious and the fact she was engaged to another man made her safe as well.
Herndon related Lincoln’s experience with a couple of prostitutes over the years also (this was NOT warmly received and did not appear in the first edition of Herndon’s LINCOLN), and said that Lincoln was terrified he’d received a STD from one. (Remember that in the 19th century syphilis was often fatal.) Some biographers have posited this as a reason for Lincoln ending his engagement to Mary Todd shortly before their first scheduled wedding and of course his depressive collapse following.
He seems to have actually proposed to Mary Owens, a woman he began courting soon after Rutledge’s death. In his early days in Springfield he became very angsty and wrote her letters basically telling her if she married him she’d be miserable and he would have no problem with her not doing so but if she absolutely insisted he would marry her- all implying there had been some sort of proposal and acceptance, at least privately. Obviously she declined which seemed to relieve him. He and Joshua Speed both paid court to Springfield’s most eligible bachelorette Matilda Edwards (sister of Ninian, who was married to Mary Todd’s sister and with whom Mary Todd lived), but Lincoln must have immediately realized that she was wayyyy above his station (attractive, cultured, an heiress, and much sought after).
All of the women Lincoln courted were above his station socioeconomically. Admittedly that’s not saying a lot since he was penniless, but being penniless on the frontier wasn’t remotely uncommon. Anne Rutledge’s father owned a farm and tavern and was one of the more affluent settlers in New Salem (not rich by city standards but compared to his New Salem neighbors he was doing well- well enough he didn’t want his daughter to settle for Lincoln- she was engaged to a man with more promise who was likely a con man). Mary Owens had inherited rental properties from her family enough to be self supporting. Matilda Edwards was from a very wealthy family and as mentioned Lincoln was really shooting too high (Speed was from a very wealthy family himself so he could aim higher).
Finally he married Mary Todd of course, and this was very much a mixed marriage socioeconomically (or to use Gore Vidal’s employment of a term that doesn’t quite mean that, hypergamy). Mary was from a rich family but had no great inheritance coming her way- her father had many children and was still having kids with his second wife when she met Lincoln. (Mary and her stepmother detested each other and in fact it’s why she was in Springfield with her sister instead of in Kentucky with her father.) Her greatest inheritance was actually from her maternal grandmother. However, though she was relatively penniless at the time he married her any inheritance was worth far more than Lincoln stood heir to, plus she was one of the most educated women in Illinois and passionate about politics and had an intellect that would have repelled some men but surely attracted Lincoln.
Of course the penalty for marrying into a much higher caste was that Mary also had a deserved reputation for being impossible to live with: a psychotic temper, continual neediness, irrational jealousy, and prone to excessive spending. Still, she gave up a LOT when she married Lincoln: he had nothing (was in fact still deep in debt when she married him), he was generally considered ugly and was 16 inches taller than she was, nobody knew he was going to be president at the time, and he had his own personality quirks: if she was needy he was prone to self absorption and often absent when he was present, he suffered from recurrent bouts of melancholy.
He also had no understanding of female personality or of the comfort level his wife was used to as his own mother and sister were long dead by this time and both were rugged pioneer women. To the women he grew up with a day’s work began before sun-up when you hauled yourself off a corn shuck mattress, went outside and drew water from a well (picking up and dropping a heavy rock to break the ice first if it was frozen), collecting eggs, milking a cow and then fixing breakfast over an open fire all as the sun is getting up, and then you have a day of backbreaking labor that often involves malnutrition and never involves new clothing. When he took Mary to live in a boardinghouse it was a place that he probably thought “Ma or sister would have thought they were in heaven here” while to Mary it was going from a mansion filled with servants and finery to a small dark room in a house full of strangers, most of them a step up from hillbillies, and the nocturnal noises of newlyweds probably being overheard and laughed at by these people you’re seeing at breakfast each morning- she gave up a LOT to be with him, and this after the humiliation of their first aborted union.
Sorry, off topic, but the point being that while Mary’s sinning gets plenty of coverage I think the degree to which she was sinned against is often overlooked. And that Lincoln’s romantic life was complicated and ultimately unknowable.
I have no idea if there was a romantic relationship with Speed. I’ve little doubt that they had sex of some sort at some point (two horny guys in a bed for four years, things are gonna come up) and that this along with genuinely loving him and confiding in him (Lincoln was a very lonely man who had no family he could relate to- he hated his father, loved his stepmother but she was toothless illiterate hillbilly with all superstitions that implied, and his brother and sister died when he was young, so Speed was like a brother and a friend and the first intellectual he’d really spent time around) and probably some awareness of Greek ideals of man:man love probably all combined to make Speed the love of his life whether he was gay or whether he wasn’t. Mary Todd was always a space alien to him: tiny, pampered, the same body parts as his sister and mother had but completely different arrangements and nothing in common with them, and then crazy- it would have made him miss Speed all the more.