Does anybody know exactly where to seek/find immigration records to the UK

from the 1870s? Specifically, I have 3 grt grt and 2 grtgrtgrt grandparents

who migrated to the UK in the 1870s. One migrated >from Russian Poland
(specifically >from Konin) and shows up on the 1871 census in London. Another came >from
Poland, probably also in the 1870s and was here by 1878. The rest came >from
what was probably Prussia between 1873 and 1878 and migrated to Birmingham.

I confess to having a hard time figuring out how to construct a proper query
on the National Archives site, so sources could be there that I have trouble
finding.

Thanks,

Janette Levey Frisch
East Windsor, NJ, USA

searching for WOOLF, NATHAN and BARNETT families in London area; LEVY and
CARO families in Birmingham area.