Which two colonies and then states had set up a unicameral legislature?

Delaware and Pennsylvania.

Explanation:

Today, 49 states have bicameral legislatures, and one--Nebraska--is unicameral. This was not always the case, however. Most of the American colonies were governed by one-house legislatures, but this gradually shifted. By 1763, only two colonies (Delaware and Pennsylvania) continued to use unicameral legislatures.

The Articles of Confederation was unicameral because the member states, the 13 colonies, wanted equal representation.  The main reason was to set down in a document, what the new government body could and could not do.  The system was really based on what would later be called states' rights.   The weaknesses included, no taxation so that there was no central government to direct national activities, no common currency.  Each state operated their own banks and some states didn't recognize other states' decrees or documents.  Further, each state had their own laws and the laws of the states overrode the laws of the article of confederation.  The constitution fixed most of these problems.  First, the Constitution made representation an issue.  Instead of the two representatives for each state there would be representation based on the total population of the states based on the censuses that would be conducted, then the representation would be based on individual state populations.  The two per state became the Senate, chosen originally by the legislatures of the various states and the House of Representatives chosen by the population of the state directly from the population of the various states.    Other problems the Constitution fixed included: taxes (don't laugh), currency and government activities.  Taxes, Alexander Hamilton's leadership as a legislator, financier and statesmen. Created the office of the treasury which allowed the US to grow.  Understanding the problems of the colonies before the Constitution there was one currency under this new system.  Government activities... The government (national) for a long time was very small for a number of reasons.  The powers that were outlined in the Constitution were the ONLY rules that were enforced by the government and ALL other powers were the pervue of the states that made up the new union.

Explanation:

d.prevent the spread of communism outside of eastern europe.