The question below consists of a set of labelled sentences. Out of the four options given, select the most logical order of the sentences which form a paragraph.

The building's history begins in 1792, when a public competition was held to choose a design for a presidential residence in the new capital city of Washington.

P. Labourers, including local enslaved people, were housed in temporary huts built on the north side of the premises.

Q. The structure was to have three floors and more than 100 rooms and would be built in sandstone imported from quarries along Aquia Creek in Virginia.

R. Thomas Jefferson, later the country's third president (1801-09), using the pseudonymous initials "A.Z.," was among those who submitted drawings, but Irish American architect James Hoban won the commission (and a $500 prize) with his plan for a Georgian mansion in the Palladian style.

S. The cornerstone was laid on October 13, 1792.

They were joined by skilled stonemasons from Edinburgh, Scotland, in 1793.