The southwest corner of 3rd & Chestnut falls right in the heart of Philadelphia’s tourist-friendly historic district.  And like much in the surrounding area, this corner has seen its fair share of change over the years.  The earliest available records, from Philadelphia Architects and Buildings, tells us that 300 Chestnut St. was the site of the Public Ledger Building.  This was erected in 1845 to house a rapidly growing newspaper operation.  The Public Ledger Building is shown in the image here below, taken from Hexamer & Locher’s 1858 Philadelphia Atlas

The Public Ledger Building, 1858

At the time, the Public Ledger was the city’s most popular newspaper but its reputation was about to take a dive.  According to Wikipedia, the paper’s official opposition to the Civil War ran contrary to passionate Union support among Philadelphians.  A photo from the Library Company of Philadelphia shows the building in 1865, after several years of war, declining circulation and a change in ownership

The Public Ledger Building under new ownership, 1865

With new ownership and a declaration of Loyalist Union support, the Public Ledger rebounded somewhat.  However, its decline helped the Philadelphia Inquirer to grow dramatically, largely based on its popular coverage of the war.  This allowed the Inquirer to move into a building directly next to the Ledger.  The neighboring competitors are shown here below, in a Historic Commission photo probably taken from the 1870s. 

The Public Ledger and Philadelphia Inquirer in the late 1800s

By the start of the 20th Century, both newspapers had outgrown the facilities at 3rd and Chestnut.  Their respective departures paved the way for a structure that would envelop the site of both buildings.  According to King’s Views of Philadelphia, the block previously known as Newspaper Row came to be occupied by “a grand substantial brick and granite office building.”  The photo below, also taken from King’s Views, shows the Mariner & Merchant Building upon its initial construction. 

The Mariner & Merchant Building upon construction, 1901

Among those who utilized the considerable office space made available by the Mariner & Merchant Building was the groundbreaking Ayer & Son Advertisement company.  According to Marketing Communications, Vol. 91, dated 1915, “300 Chestnut Street, Philadelphia is the business home of a number of men with such experience.  We have been remarkably successful in serving small businesses advertisingly.”  By the mid-20th century, Ayer & Son would serve businesses advertisingly from a new location.  300 Chestnut Street was converted into a Post Office, as shown in the Works Progress Administration Land Use Map image below.

A Post Office in 1942

Following World War II, a heightened sense of patriotism contributed to the historical designation of the grounds stretching between 2nd and 6th Streets on Chestnut.  This would become the Independence National Historical Park in 1948.  Though the Post Office would remain on site for at least another 15 years, it would be surrounded by public park space.  Eventually, said space would eclipse the Post Office and lead to its demolition.  Today, the area formerly known as 300 Chestnut is remade to reflect its colonial past, which has ironically obscured the corner’s subsequent 200 years of change. 

A lush corner of the Independence National Historical Park, 2014