He is noted for expansive real estate developments in Milwaukee, including the luxurious Plankinton House Hotel designed as an upscale residence for the wealthy.

He expanded this industry and eventually became acquainted with the meatpacking industrialist Philip D. Armour forming a company with him that lasted for 20 years.

He donated the land for the construction of the Perseverance Presbyterian church and supported the formation of a soup kitchen in Milwaukee for the poor that included the daily supply of meat needed.

[1] In 1832, when he was 12 years old, the family moved to Pittsburgh,[9] where he attended public schools and received most of his early formal education.

[14] Plankinton was disappointed and upset over the lack of confidence, so with his capital of $400 ($13,100 with inflation[15]) he built a general store in opposition and operated it for a few years and lived above the business.

[23] The newly formed company was fueled by meat demand for the Union Army troops in the American Civil War and thereby became successful.

[27] They moved the entire facilities in 1893 about 2 miles (3.2 km) from the Milwaukee city limits to a 700-acre (280 ha) parcel of farm land known unofficially as "Porkopolis".

[29] When Milwaukee was incorporated as a city in 1846, the American House Hotel in the center of town on Grand Avenue had been operating for three years.

Built as an upscale hotel intended for business people and the wealthy, its frontage occupied 800 feet (240 m) on Grand Avenue.

Inside was an elegant dining room that matched those of the most expensive hotels in the world and could accommodate over 300 people.

[31][32] Plankinton's luxurious hotel had a mansard roof and was the tallest building in Milwaukee at the end of the 19th century.

[49] The scale of the value of the property can be inferred from the $5,000 spent to add a carriage barn just after the mansion was completed, as at the time $750 was sufficient to build a country cottage and $7,000 was enough for a major stone-and-brick villa.

The construction supervisor, described as a master mechanic, was Arthur Bates who had built many mansions and handled the renovation of Plankinton's own property.

He was involved with business affairs of the livestock producers of Wisconsin and northern Illinois by developing a market for their products in Milwaukee.

[59] He also supported the formation of a soup kitchen to feed the poor, by providing the building rent-free, along with a generous amount of money, and a daily supply of meat.

[60] He died of pneumonia in his home on the evening of March 29, 1891,[45] attended by his family, personal business secretary Jeremiah Quin,[61] and his long-time medical doctor Dr.

[55][62] He was buried in the Forest Home Cemetery in Milwaukee[2][63] and a large monument and pillar is built on the site.

A newspaper obituary reads: "Milwaukee today mourns the loss of her foremost citizen, whose generous public spirit and many deeds of benevolence, whose great business ability and modest, upright life are imperishably written on the pages of Milwaukee's history.

[67] It included contributions from Cudahy, Frackelton, Frank Gunsaulus, General Charles King, Layton, and Quin.