Acts 17:1

Paul, Silas, Timothy, and perhaps others left Philippi and headed southwest on the Egnatian Road. Luke evidently stayed in Philippi since he again described Paul’s party as "they" instead of "we" (cf. Acts 20:5-6). Paul and Silas probably stayed overnight in Amphipolis, which is 33 miles (a day’s journey by horse) along the Egnatian Way. It stood at the mouth of the Strymon River. The next day they travelled another 27 miles farther west-southwest to Apollonia. Another 35 mile day of travel farther west on the Via Egnatia took them to Thessalonica (modern Salonika) on the Thermaic Gulf of the Aegean Sea. The text does not state that Paul’s party stayed only overnight in Amphipolis and Apollonia, but most interpreters have inferred this from the narrative. Luke recorded more information concerning the apostles’ ministry in Thessalonica, where they stayed for some time. Thessalonica was the chief city and capital of Macedonia, about 100 miles from Philippi. As such it was a strategic center for the evangelization of its region (cf. 1 Thessalonians 1:7-8).

"Thessalonica was a ’free city,’ which meant that it had an elected citizens’ assembly, it could mint its own coins, and it had no Roman garrison within its walls." [Note: Wiersbe, 1:470.]