The first settlers to arrive in California after the Native Americans were Spanish.
Mexicans built settlements in California up until 1848 because that territory belonged to Mexico. After the Treaty of Hidalgo it became the territory of the United States.
They placed troops and built forts/ missions/settlements.
The Spanish built both forts and pueblos as defenses in their settlements. The borderlands ran west from Florida to California.
European nations built empires in the Americas through a combination of exploration, conquest, and colonization. They established settlements, claimed land, and exploited local resources, often using military force against Indigenous populations. The introduction of diseases, to which Native Americans had no immunity, significantly weakened these populations, facilitating European control. Additionally, European powers utilized trade networks and alliances with certain Indigenous groups to strengthen their foothold in the region.
European nations built up their armies by propaganda, war bonds, switching civilian factories to firearm, tanks, and war material factories.
St. Augustine built the first permanent, or long-lasting, European settlement in what is now the United States.
Presidios were built to protect the Spanish settlements from attack.
boston
French
Lakes
So that during wars they could go fight for and protect Eastern Europe.
No, you cannot build roads through settlements in Catan. Roads must be built adjacent to settlements or cities.