St. Petersburg is a city in northwestern Russia, situated on the Neva River, at the head of the Gulf of Finland on the Baltic Sea. It was founded by Tsar Peter the Great on May 27, 1703, and became the capital of the Russian Empire for more than two hundred years (1712–1728, 1732–1918) 1. The city was built under adverse weather and geographical conditions, and the high mortality rate required a constant supply of workers. Peter ordered a yearly conscription of 40,000 serfs, one conscript for every nine to sixteen households. Conscripts had to provide their own tools and food for the journey of hundreds of kilometers, on foot, in gangs, often escorted by military guards and shackled to prevent desertion, but many escaped; others died from disease and exposure under the harsh conditions.
Source: Wikipedia
The year 1861 was a watershed year in Russian history, best known for the emancipation of the Russian serfs. It was also a major breakpoint for migration into and out of the Russian empire and for Russia's openness to the outside world. From the 1850s to the 1860s, according to Lohr, immigration into Russia increased by a factor of five. There was a net immigration of 4.5 million people into Russia between 1860 and 1917. Up to 500,000 guest workers were entering and leaving the country each year by the end of the imperial period.
Source: F. Joseph Dresen, Kennan Institute
Church record duplicates for St. Petersburg online at FamilySearch: https://www.familysearch.org/search/image/index?owc=M6VL-RMS%3A295801501%2C296754301%3Fcc%3D1469151