The shogunate, always suspicious of people on the move, maintained a system of garrisons along the road, and no one went through without an official pass.
The shogunate thought a garrison would keep terrorists out.
mnli hypothesis: The shogunate thought a garrison would keep terrorists out. premise: The shogunate, always suspicious of people on the move, maintained a system of garrisons along the road, and no one went through without an official pass.