Alma 53:22

And now it came to pass that Helaman did march at the head of his two thousand stripling soldiers, to the support of the people in the borders of the land on the south, by the West Sea.

Helaman led his two thousand young soldiers to help the people at the borders of the land on the south by the West Sea.

Helaman marched at the head of his two thousand young soldiers to reinforce the people defending the southern border along the West Sea.