{And Timothy} (kai Timotheos). Timothy is with Paul, having
been sent on to Macedonia from Ephesus ( Ac 19:22 ). He is in no
sense co-author any more than Sosthenes was in  1Co 1:1 . {In all
Achaia} (en hol(8869) t(8869) Achai(8369)). The Romans divided Greece into
two provinces (Achaia and Macedonia). Macedonia included also
Illyricum, Epirus, and Thessaly. Achaia was all of Greece south
of this (both Attica and the Peloponnesus). The restored Corinth
was made the capital of Achaia where the pro-consul resided ( Ac
18:12 ). He does not mention other churches in Achaia outside of
the one in Corinth, but only "saints" (hagiois). Athens was in
Achaia, but it is not clear that there was as yet a church there,
though some converts had been won ( Ac 17:34 ), and there was a
church in Cenchreae, the eastern port of Corinth ( Ro 16:1 ).
Paul in  2Co 9:2  speaks of Achaia and Macedonia together. His
language here would seem to cover the whole (hol(8869), all) of
Achaia in his scope and not merely the environment around
Corinth.