Here are some topics and presidents you can study that would help with this assignment.
Teddy Roosevelt (1901-1908) - Preservation of national parks and forests. - Meat Inspection Act: This helps to protect American consumers from businesses who were previously selling tainted meat. - Panama Canal- This important waterway connected the Atlantic and Pacific Ocean.
Abraham Lincoln (1861-1865) - Emancipation Proclamation - Lead Union to win in the Civil War. - 13th amendment- This gets rid of the institution of slavery in the United States.
As ancient Rome expanded it's influence it allowed it to interact with different regions and began to trade. Also the trade routes helped it a lot. Hope this helps!
