Why did the Federalists believe the national government would not become too strong if the Constitution was adopted?

The Federalists felt that this addition wasn't necessary, because they believed that the Constitution as it stood only limited the government not the people. The Anti- Federalists claimed the Constitution gave the central government too much power, and without a Bill of Rights the people would be at risk of oppression.

according to worldatlas.com, the u.s. has an 86% literacy rate.

it was certainly a debatable decision, mainly because it was based primarily on political - and not on legal or social - views. since the congress at that time was led by members of the republican party, and the territory that the tribes wanted to turn into an exclusively indian state was predominantly democratic, the proposal (as expressed in the constitution) did not succeed, but the constitution itself proved to be of crucial importance in the creation of the state of oklahoma, and, most importantly, it guaranteed the involvement of representatives of the indian tribes in the government of the future joint state.  

as a member of congress, i would have voted to ratify the constitution, or at least to have it tabled. ignoring it was an interested and partial decision.