I know that in different times of human history and among different cultures, the definition of 'beauty' has a tendency to change.
I am currently reading a lot of history on America during the American Revolution. In doing so, I often times reference the portraits of people they mention in the texts. I like to put a face to a name. I am taken aback by how often women they that are noted as 'striking' often times just seem kinda unappealing to me. Maybe even sometimes gruff or weathered in appearance?
It's unclear to me whether this has to do with the artistic style of the portraits at the time, a different understanding of beauty, or other factors that could come into play such as when in their life the portrait was drawn.
Regardless, how have definitions of beauty changed in America from the time of the Revolution?
It's difficult to generalize standards of beauty for any time, since they are such a personal thing. However, for the 1770s and 1780s there were certainly some more universally sought traits. Pale, porcelain skin with rosy cheeks and lips, often achieved through use of rouge. The eyebrows were sometimes darkened, though a lighter tone of hair color was achieved through the process of pomading and powdering. Darker powders were available as well, but the grey tones you see in so many portraits were due to the white or grey powder that was so popular (black, brown, rose, blue, lavender, etc were also available). The fashions were transitioning during the years of the Revolution. The hair lost it's height and became more of a mass of frizz and curls all about the head. Instructions call for this style to be kept light and ethereal. Clothing followed suite and lighter silks and cottons were incredibly fashionable. For the figure, in the early 1770s fuller hips were still emphasized and balanced by larger sleeve ruffles that kept the illusion of dainty arms. This, combined with the higher hairstyles, created a triangle silhouette. Very balanced and geometric. As we reach the 1780s, the natural, rather than geometric, is much more popular. Emphasis goes to the bosom and the rear. False rumps fill out the large skirts and gauze kerchiefs the open neckline.
I'm not sure which particular women you've seen in your books, but there were quite a few women noted for their beauty. Sticking to some of the more well known we have Lady Hertford who was eventually mistress to King George IV. Mary Robinson as Perdita, she was also a mistress to King George IV before he was king, but was quite a celebrity in her own right. Famous at the same time was Elizabeth Armistead. Emma Hamilton later won over Horatio Nelson, but was famous during this time in part due to George Romney's love of painting her in Classical scenes. Jumping back to the early 1770s Madame du Barry was the mistress of King Louis XV.
Remember that just like today those that are famous for their beauty are generally set up to be famous due to their connections, family, career (actors), etc. And even then, their level of beauty is never agreed upon by all. We all know plenty of attractive people who are not famous in any way, and it was much the same then. You're more likely to find an array of what you would consider attractive by looking through the portraits of less infamous women. Pinterest is an oddly great resource for portraits.