How does the author make the transition from 1862 to the first encounter between March and Marmee?

In this section, March uses the first encounter he'd ever had with marmeee to lighten the tone of his letter. They had met during a mass funeral for seven men who had lost their lives in a battle. One of these men's bodies, a black man, was not permitted to be part of the funeral even though he had died fighting for the same cause as the white soldiers. March was incensed, but agreed to speak at the funeral anyway. He included the black man's death in his speech, despite the outcry. In the audience, a young woman's dark eyes encouraged his speaking, alight with agreement. The girl was Marmee Day, the younger sister of March's good friend. Over dinner, March found himself falling desperately in love with her.