America has a long established two-party system with the Democratic Party and the Republican Party; it has been argued that the UK too, has a two-party system. If we accept the key assertion that the UK does have a two-party system then it is necessary to compare the differences and similarities of how these four parties have developed.
In the US, both the Republican and Democratic Party have emerged from factions. For example the Democratic Party began as a faction of men who were anti-federalists, likewise the Republican Party formed as a result of men in other parties opposing slavery. Compare this to the UK and it is clear that the Conservative Party formed through factions, splitting off from the Whigs. This would show a strong similarity between both the development in the US and UK, as they have all derived from factions.
However, the Labour party arose from trade unions and the need of the urban proletariat who wanted representation in the Commons. Therefore it is necessary to recognise that the development of political parties in the USA and UK is similar to some extent, however this similarity is hindered by Labours evolution from Trade Unions.
Likewise, all parties were influenced by key events in their development. However, the nature of the events that influenced them differed, for example the development of parties in the USA was heavily influenced by slavery and civil rights. The Republicans wanted the abolishment of slavery for economic reasons, whereas the Democrats wanted to keep slavery as it enabled the Southern economy to flourish. Whereas in the UK the development of political parties was focused upon class, Labour emerged as the working class wanted people to represent them in politics, as they believed the elite of the Conservative party did not understand their needs. So whilst both the UK and USA parties have been influenced by major themes, they are