Answer:
The three States are:
1. Michigan
2. Ohio
3. New Hampshire
Explanation:
These States often receive the most expensive and targeted campaigns during elections since they are considered as 'Swing States'
Unlike 'Safe States' which are generally inclined towards one party, Swing States have a history of changing sides and voting for someone new in every election.
One year they might support a democratic candidate, while in another, they might side with the Republicans. Since it is extremely difficult to predict what they will do, and their decision plays a huge role in who wins the election, they are called 'swing States' and receive a lot of attention.
The Taj Mahal was built during the Mughal rule in India.
If you're asking in general then, the area has to have people who share common customs, belief and language.However, this might not entirely be true as there are some countries which have vast diversity and still portray nationalism.
Hope this helps!!