The four flags are those of nations who have ruled New Castle: Holland from 1651, Sweden in 1654, then the Dutch again a year later then England in 1664. William Penn was granted Pennsylvania in 1682 and the "Three Lower Counties" (Delaware) a few years later. The northern border of the county is an arc 12 miles from New Castle.
The building is listed as a National Historic Landmark. This central part of this Georgian style building was built around 1732, replacing an earlier structure burnt in unsuccessful escape attempt of a prisoner. The fireproof west section with minimal interior wood finish and east sections were added later. This building was the state capitol until 1777 when it was transferred to Dover due to the threat of British invasion.
The General Assembly meeting upstairs on June 15, 1776 declared independence from England and from Pennsylvania.
Across the street at 212 Delaware is a building constructed in three different times showing three different building styles. The central part has the string or belt course characteristic of Georgian Style Houses. The left portion, built by state Chief Justice James Booth Sr. in 1790 shows that when it was constructed, that details was no longer in style, though he did carry over the dentil molding in the cornice. He later added the wooden law office to the right.
The Wilmington Trust bank to the left of the Booth house was once the Gilpin house tavern. The arch in the modern facade reproduces the former entry way for deliveries by horse drawn beer wagons.