under arms

Many of the Germans were under arms at all hours of the day and night.

Thousands were under arms, gathering at Cambridge and Roxbury.

At three o'clock in the morning the army was, as usual, under arms.

The troops were under arms, but the bridge was not finished.

The fortress was under arms indeed, but she had no navy to speak of.

The garrison of Detroit was under arms to receive His Majesty's representative.

And we hold the land: in all their thousands the nations of Italy are under arms.

The whole camp was under arms, and ammunition and reinforcements were sent.

The troops all got under arms, and parties were sent out to the outposts.

Our regiment was ordered to be in readiness to march, and was under arms two hours.