Lawrence Washington's spouse Anne Fairfax was from a prominent West Indian family of multiracial origin. Their ancestry was visible to the extent that father George William Fairfax worried that his children's features would limit their advancement in British high society.
Was this a big deal at the time? I've never heard of other slaveholding families in the English colonies having a mixed-race origin, and from what I understand legitimate interracial relationships were discouraged our outlawed well before the establishment of Jim Crow.
What was the broader social context of Lawrence Washington's marriage? Were wealthy white planters more able to pursue matrimonial relationships with non-white women in the 18th century than they would be in the 19th century?
What was the broader social context of Lawrence Washington's marriage?
Anne Fairfax (her mother's maiden name was Cary) was not from a prominent West Indian family of multiracial origin. She was from an old Virginia planter family that dated to the 17th century. While it's true not much is known about her mother since a fire destroyed some family records, she too came from a prominent Virginia family (or, by a shocking coincidence, had the same maiden name as one of them). We have portraits of her mother, Sally and Sally's birth family. They do not have African features.
George Fairfax and his sister, meanwhile, were from a prominent English family that had ties to the West Indies. His father was related to minor nobility, in fact. He married a woman named Sarah Walker, who might have been mixed race. There is scant evidence about her in general and the idea that she might have been mixed race comes from one line in one letter: "I have no reason to doubt any of their indulgences to a poor West India boy especially as he has the marks in his visage that will always testify his parentage."
The reference to being West Indian could mean being mixed race. It could also be a geographic signifier. We do have portraits of George and he also lacks significant African features though he does have slightly darker skin than was normal. Based on the portraiture, one historian argued the line is referring to being tanned from the Caribbean sun. Others have argued Sarah had some mixed blood. It is known that during later periods, the family sometimes omitted these lines and thought they would make them look bad. But there is no question both father and son qualified as white under the legal-racial schemes of the time.
So, the broader context was less interesting than you wanted. It was acceptable for gentry from one part of the British Empire to marry gentry from another part.
Were wealthy white planters more able to pursue matrimonial relationships with non-white women in the 18th century than they would be in the 19th century?
It depends on location and specific time period. The 19th century has both Reconstruction, when many states repealed such laws, and the Redemption, when they were reinstated even more harshly. On the other hand, the longest continuous legalization is in Pennsylvania which explicitly allowed mixed race marriages in 1780 and has never restricted them since. Some other states never enacted restrictions at all, like Connecticut.
In Virginia specifically, mixed-race marriages were legal until 1691 (so for 74 years). Like most things in Virginia at that time, this was a privilege that accrued to the upper class. There were earlier laws regulating or banning marriages between, say, white indentured servants and slaves. Notably, these laws were not just concerned with whites and blacks. It was also concerned with mixing of social station (free and indentured or enslaved) and with Native Americans, Indians, etc. The laws were reaffirmed after the Revolution. During Reconstruction, the effort to repeal them failed, however they were effectively unenforced in Virginia. When the Redemption occurred, the laws were enforced again and strengthened during Jim Crow. An even harsher law was passed in 1924. They were eventually abolished in 1967 due to the aptly named Loving vs Virginia.
The century with the most freedom to marry interracially was thus the 17th, at least if you were one of the elite. It was de jure illegal for everyone for the entire 18th and 19th century and two thirds of the 20th, with small de facto interruptions. It was eventually repealed in the late 1960s.
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