Verses with the word horsemen in the New Testament (3 verses):

Acts 23:23
And he called unto him two centurions, saying, Make ready two hundred soldiers to go to Caesarea, and horsemen threescore and ten, and spearmen two hundred, at the third hour of the night;

Acts 23:32
On the morrow they left the horsemen to go with him, and returned to the castle:

Revelation 9:16
And the number of the army of the horsemen were two hundred thousand thousand: and I heard the number of them.