Answer:
Abandoned horses.
Explanation:
They were a couple from Indiana who left toward California because they were in the search of gold during the Gold Rush. They traveled 2,000 miles with a wagon and when they passed through the desert they saw a lot of abandoned horses.
They eventually settled down on Sacramento, where Margaret write down a diary about their journey, it still remains as a classic account of American pioneer history.
I hope this answer helps you.
