From about 1843 onwards the minstrels were immensely popular on both sides of the Atlantic, until the Music Hall boom c1850 in fact. Minstrel songs largely consisted of pseudo darky songs in a playful dialect, and sentimental songs about loved ones dying or being far from home. Once the Music Hall took off there was a much greater 'variety'. Comic songs in character, moral songs, still lots of sentimental stuff, patriotic, occupational, dialect songs.
there are plenty of books on the minstrels and the Music Hall.