A Growing Nation

4. a machine that sends and receives signals through a thin wire
6. an area of land that includes a house and its buildings
7. a shot with a weak virus that helps people's bodies fight off disease
9. each worker does only one part of a job
10. a person who moves from one country to settle in a different country
11. someone who works to make a change happen
13. a time period in the 1840s when thousands of people came from around the world to California to search for gold
14. the scientific knowledge about how things work
16. something that is made for the first time
17. keeping people out of a place
18. money that is paid for using a road

1. train a group of covered wagons that travels together for safety
2. a region that forms the edge of a settled area
3. when all people have the same rights
5. a document that gives a person the right to be the only one making or selling an invention
8. a waterway that is dug by people
12. to pass thoughts or information to others
15. across the continent