Owned vacant land for 22 yrs., sold, made 15k profit. Do I add that to our joint filing of our regular income of 60k and also have to pay more in capital gains?

Property was put in my name 22 years ago by my father.  I don't understand if I have to add it as regular income and then pay capital gains taxes on it.  I was told that I would not add it to our income, and would not owe any capital gains taxes either.  That didn't make sense to me since I made a profit of 15k.