It's quite rewarding to take your start from any clues the songs themselves might hold
Songs like Lady in her Father's Garden probably have their roots in the 'broken token' tradition which possible has its roots in the 'Gimmel Ring' tradition of making a match with an especially manufactured ring which breaks into two (three in earlier days) to be given to each of the betrothed, and a witness, among the better off

Many of the poaching and transportation songs were inspired by the many centuries seizures of Common land (which have their own interesting history)

The 'Can I go along with you' songs are obviously referring to the armies of 'Camp Followers' made up of wives, prostitutes. tradesmen, etc., which followed the troops into war
SOME INTERESTING INFORMATION TO BE HAD ON THIS

The Ballad of 'Tiftie's Annie' - is crammed with background history - the replacement of the Gentry by the new Trading Classes - the use of female members of the family as a way to climb the social ladder, the lengths ruthless heads of the family would go to protect their female 'assets' -    accusations of the use of witchcraft as a love charm - with a bit of the Edinburgh witch trials thrown in for good measure (with a possible trip to Fyvie Churchyard to see the grave to top it all off)

All good fun and far more fruitful than chasing the rainbows of 'original versions)
Jim Carroll