In the mid 1700s (in New England) there was a shift in courtship ritual from parents being very involved to a more "modern" romantic version where the children had more control. Conversely the number of premarital pregnancies shot up from 1 in 10 to 1 in 3. The idea of marriage for love also became fairly common in the literature of the late 1700s. There was also a rise in the custom of bundling from the mid to late 1700s. So no it wouldn't be uncommon for a wife and husband to have a passionate marriage. You get a shift in the mid-late 1800s to Victorian sensibilities which were more prudish.

If you're thinking more specifically about John and Abigail Adams then there's no doubt that they were fairly passionately in love. Their first child was born 8 months and 2 weeks after they were married. They exchanged more than a thousand letters, some of which were very schmoopy and/or explicit. Here's a great NPR article on it http://www.npr.org/templates/story/story.php?storyId=130862704