Marble eventually surpassed sandstone as the most common construction material in Washington. The earliest marble originated from a stratum of stone known as Cockeysville Marble, which came from quarries in the Piedmont provinces of Cockeysville and Texas, Maryland, just north of Baltimore. This marble was used for public buildings, including the US Capitol. The city's next supply of marble was called White Marble or Federal Marble. It too came from quarries in the Piedmont region of Virginia. This marble was used for federal buildings, including the White House and US Capitol. After the War of 1812 ended, the government decided to expand its capital city by adding more land. One site considered for a new district was near the Potomac River, where there was much limestone rock available for quarrying. The government ordered a survey of this area to find out more about the quality of the rock and how easy it would be to transport away. The surveyors reported back that they believed they could build a wall with limestone blocks large enough for their purposes. State officials then announced that bids would be accepted for the building project. A company from Pennsylvania named James McKenzie was the lowest bidder with his estimate of $1 million. (About $11.5 million in today's dollars.) His business partner was a man named William Johnson, who had also been involved in the construction of Philadelphia's Benjamin Franklin Parkway.