Question: Martin Elbourne had her first job here, what grade was the House listed as?

<P0-S0>  His first job, at age fifteen, was working for the local stately home Knebworth House which in the mid-seventies became the biggest venue in the United Kingdom for outdoor shows and hosted bands such as Led Zeppelin, The Rolling Stones and Pink Floyd. <P0-S1> Martin Elbourne (born 19 January 1957 in Carlisle, Cumbria) is an English performing arts promoter. <P0-S2>  Elbourne was brought up near the village of Knebworth, Hertfordshire. <SEP> <P1-S0> Marshlands Plantation House, in Charleston, South Carolina, is an historic plantation house listed in the National Register of Historic Places on March 30, 1973. <P1-S1>  A 2 ⁄ -story Federal-style plantation home, it was built in 1810. <P1-S2>  The house was relocated in the 1960s from its original location on the site of the United States Navy Shipyard. <P1-S3>  The Navy had announced it would have to demolish the empty house if it could not be relocated with $15,000 it had set aside for the purpose. <P1-S4>  The City of Charleston took temporary possession of the house, transferring it to the College of Charleston which relocated it for preservation to James Island. <SEP> <P2-S0>  It is a Grade II* listed building. <P2-S1> Knebworth House is a country house in the civil parish of Knebworth in Hertfordshire, England. <SEP> <P3-S0> There are 20 Grade I listed war memorials in England, out of over 3,000 listed war memorials. <P3-S1>  In the United Kingdom, a listed building is a building or structure of special historical or architectural importance; listing offers the building legal protection against demolition or modification, which requires permission from the local planning authority. <P3-S2>  Listed buildings are divided into three categories—grade I, grade II*, and grade II—which reflect the relative significance of the structure and may be a factor in planning decisions. <P3-S3>  Grade II accounts for 92% of listed buildings, while grade II* is an intermediate grade accounting for 5.5%; grade I holds the remaining 2.5% of listed buildings and is reserved for structures of exceptional significance. <P3-S4>  Grade I listed war memorials are deliberately very few, though several have been upgraded to grade I status as part of commemorations around the First World War centenary. <P3-S5>  A war memorial listed at grade I will be of exceptional interest for its design and artistic merit and will be of great historical interest. <P3-S6>  Such memorials are often the work of famous architects or sculptors, amongst the most prolific of whom was Sir Edwin Lutyens, whose memorials account for a third of all those listed at grade I. Lutyens designed dozens of war memorials across the United Kingdom and elsewhere in the Commonwealth, including the Cenotaph on Whitehall in London—the focus for the national Remembrance Sunday services—and the Arch of Remembrance in Leicester—the largest of Lutyens' war memorials in Britain; both are listed at grade I. <P3-S7>  As part of the commemorations of the centenary of the First World War, Historic England—the government body responsible for listing in England—is running a project with the aim of significantly increasing the number of war memorials on the National Heritage List for England.