What caused the palmer raids

Study the graph and then complete the analysis of the data by filling in the missing information.

As the coach of the u. s. olympic cycling team, i can state without question that the swedish and french teams were using illegal steroids. how else could they have beaten us so badly in the last competition? the u. s. team trained much harder and was much more skilled than our opponents. we only lost because a few teams cheated.

Which would be good historical evidence when studying manifest destiny?