Yes Brenda, South 2nd Street and Harding Avenue are the same street between South 1st and South 3rd. 1821 is between Idaho Street and McKeen Street. The census district you are looking for is District 7. It appears a Liffick family was living at 1821 in 1930. If you have a subscription to Ancestry.com you will find it at Indiana>Vigo County>All Townships>District 7>Page 11 of 50.
What is interesting is a Bell family at 1823 S 2nd St on page 11. This family is carried over to page 12 at 1823 Harding Ave. Go figure.