Counting fourteen years from Paul's conversion (1:15–17), instead of from his previous visit (1:18), fits well with the events in Acts.
The Galatian Christians knew who Barnabas was. This suggests that Paul and Barnabas first shared the good news about Jesus with them during their first missionary trip together (Acts 13:4–14:26; see Galatians Book Introduction, "Recipients").
Titus was a non-Jewish believer who worked closely with Paul to help lead and strengthen churches. For more on Titus, see the "Titus" Profile.