"Giving away the bride" used to be a literal transaction
For many brides, a wedding would not be complete without her father walking her down the aisle. Although the current version of this tradition is a way to honor dear old dad, its history is much less sentimental. A father giving away his daughter in marriage was once just literally that: a transaction.
Fathers would give away their daughters as brides to square up debts or settle disputes, according to Southern Living. Modern brides are not being offered up to the groom's family as a bribe — at least one would hope not — so the tradition remains as a gesture of goodwill toward the father.