Pittsburgh ( PITS-burg) is a city in the Commonwealth of Pennsylvania in the United States, and is the county seat of Allegheny County. As of 2017, a population of 305,704 lives within the city limits, making it the 63rd-largest city in the U.S. The metropolitan population of 2,353,045 is the largest in both the Ohio Valley and Appalachia, the second-largest in Pennsylvania (behind Philadelphia), and the 26th-largest in the U.S.
Located at the confluence of the Allegheny, Monongahela, and Ohio rivers, Pittsburgh is known both as "the Steel City" for its more than 300 steel-related businesses and as the "City of Bridges" for its 446 bridges. The city features 30 skyscrapers, two inclined railways, a pre-revolutionary fortification and the Point State Park at the confluence of the rivers. The city developed as a vital link of the Atlantic coast and Midwest, as the mineral-rich Allegheny Mountains made the area coveted by the French and British empires, Virginians, Whiskey Rebels, and Civil War raiders.
Photo credit: Andy from Pittsburgh, United States
Sunset over downtown Pittsburgh
The Three Sisters
are three very similar self-anchored suspension bridges
spanning the Allegheny River
in downtown Pittsburgh
at 6th, 7th, and 9th streets, generally running north/south. The bridges have been given formal names to honor important Pittsburgh residents:
Designed by the Allegheny County Department of Public Works, they were all built in a four year period, from 1924 to 1928, by the American Bridge Company, replacing earlier bridges of various designs at the same sites. Their construction was mandated by the War Department, citing navigable river clearance concerns. They are constructed of steel, and use steel eyebars in lieu of cables.
The Three Sisters are historically significant because they are the only trio of nearly identical bridges, as well as the first self-anchored suspension spans, built in the United States. They are among the only surviving examples of large eyebar chain suspension bridges in America, and furthermore, unusual for having been erected using cantilever methods. The bridges' design was viewed as a creative response to the political, commercial, and aesthetic concerns of Pittsburgh in the 1920s.
Rachel Louise Carson
(May 27, 1907 - April 14, 1964) from Springdale
was an American marine biologist
and nature writer
whose writings are credited with advancing the global environmental movement
Carson started her career as a biologist in the U.S. Bureau of Fisheries, and became a full-time nature writer in the 1950s. Her widely praised 1951 bestseller The Sea Around Us won her financial security and recognition as a gifted writer. Her next book, The Edge of the Sea, and the republished version of her first book, Under the Sea Wind, were also bestsellers. Together, her sea trilogy explores the whole of ocean life, from the shores to the surface to the deep sea.
In the late 1950s, Carson turned her attention to conservation and the environmental problems caused by synthetic pesticides. The result was Silent Spring (1962), which brought environmental concerns to an unprecedented portion of the American public. Silent Spring spurred a reversal in national pesticide policy--leading to a nationwide ban on DDT and other pesticides--and the grassroots environmental movement the book inspired led to the creation of the Environmental Protection Agency. Carson was posthumously awarded the Presidential Medal of Freedom by Jimmy Carter. Her childhood home is preserved and listed on the National Register of Historic Places. Also near Pittsburgh, a 35.7 miles (57 km) hiking trail was dedicated to Carson and one of the city's Three Sisters bridges was renamed in her honor.
North Shore Riverfront Park
is a small municipal park along the north banks of the Allegheny
and Ohio Rivers
across from Downtown Pittsburgh
, United States
. It is a parcel of Three Rivers Park
, the city's urban waterfront park along its rivers that provides a continuous green trail link between existing and future riverfront destinations including the Carnegie Science Center
, Heinz Field
, PNC Park
, and the Three Sisters
bridges. The approximately one mile (1.6 km) long park offers walking and biking trails with unobstructed vistas of the cityscape. Boat tie-ups are located along the park to encourage water recreation. In front of each stadium is a large cobblestone quay that handles canoes and kayaks, as well as larger vessels.
Other features include Kayak Pittsburgh which supplies kayaks and bikes for rental, the Water Steps (an interactive fountain), and the Market Street Pier. North Shore Riverfront Park also houses three memorials: the Korean War Veterans Memorial, the Vietnam Veterans Memorial, and the Law Enforcement Officers Memorial.
On this day in Pittsburgh history...
- (1800) The Tree of Liberty becomes the city's 2nd newspaper with Hugh Brackenridge as editor.
- (1890) At Rec Park v Chicago, Pirates ace Bill Phillips is the 1st & still only to give up 2 grand slams in a single NL game.
- (1907) Pittsburg, Oklahoma is founded, as one of the 47 worldwide Pittsburghs, Pittsburgs, or Pitsburgs places honoring the Steel City by name.
- (1909) At Forbes Field v New York, Pirates star Ham Hyatt sets the MLB record with his 3rd pinch-hit triple of the season.
- (1911) Pirates ace Elmer Steele throws just 72 pitches at the Dodgers with no walks, no Ks & no hits until a 1 out single in the 9th that escaped Dots Miller as hall-of-famer Honus Wagner suffers a 25 game injury.
- (1913) Pirates hall of famer Honus Wagner goes 4-5 with a homer at New York to lead the team to an 8-6 win over Christy Mathewson who dueled Babe Adams.
- (1943) USS LST-285 is laid down at Ambridge.
- (1947) Pirates star Ralph Kiner is the 29th to hit 3 homers in a single NL game as he ties the MLB record with 7 homers in 4 games, 6 in 3 games, 5 in 2 games, & 4 in consecutive at bats. Hank Greenberg & Billy Cox both add another 2 homers each, setting the MLB record for most players with multiple homers in a game during a Forbes Field win over St. Louis.
- (1952) Washington hosts the 1st PONY World Series.
- (1956) US Steel announces $738 millionia in McKeesport expansion.
- (1958) Pirates star Frank Thomas is the 65th to hit 3 homers in a single NL game in a win at Cincinnati.
- (2000) Penn Hills' Turner Dairy is the areas last to discontinue home delivery.
- (2000) 
- (2006) Pittsburgh International begins Valet Parking for travelers.
- (2008) It's the single best management team in all of baseball, maybe all of sports. 
- (2009) World news focuses on Howard Dean & Bill Clinton as the convention center hosts Netroots where Clinton is heckled about Don't Ask, Don't Tell responding off-script why his goals on the issue failed.
- (2011) Bing homepage features Pittsburgh skyline. (confirm this)
- (2011) Andrew McCutchen hits a 3 run homer for the lead as Neil Walker hits a bottom of the 9th homer to rally for a tie before Garrett Jones goes yard in the 11th for 5-4 win v St. Louis at PNC Park as Pirates ace Jeff Karstens pitches Albert Pujols' MLB record setting 30th homer for the 11th straight season.
- (2012) At PNC Park v the Dodgers Garrett Jones homers twice as Pirates ace AJ Burnett surrenders one to Hanley Ramirez who taunts the team as he rounds the bases only to have AJ strike him out on a 3-2 pitch in the 6th as he shouts from the mound to S.T.F.U.
- (2013)  wedding and Willie Robertson visits.
- (2013) A 2 day archaeological dig is conducted at the Ft. Pitt blockhouse.
- (2013) HJ Heinz announces it will move out of 276,705 sq. ft. on 6 floors of its 6th Street North American headquarters.
Did you know...
- ...that Litchfield Towers is the largest and tallest dormitory at the University of Pittsburgh's main campus, at 22 stories in height and housing over 1,850 residents?
- ... that Emil John Mihalik, the first Byzantine Eparch of Parma, was born in Pittsburgh, Pennsylvania?
- ... that the 23 home runs hit by Johnny Rizzo in 1938 set a Pittsburgh Pirates team record at the time, and his nine RBI in a 1939 game set a single game team record that still stands today?
- ... that the American Iron and Steel Institute formed the Steelmark in 1960 to promote American steel, with the logo put on the helmets of the Pittsburgh Steelers in 1962 to further publicize the program?
- ... that William J. Winter, while serving as auxiliary bishop of the Roman Catholic Diocese of Pittsburgh, confirmed an estimated 45,000 Catholics?