A monopoly occurs when a single company or person controls the entire supply of a product or service in a market, meaning there are no other competitors. This can lead to higher prices and fewer choices for consumers because the monopolist doesn’t have to compete with anyone else. Monopolies can be problematic because they can limit innovation and take advantage of customers without fear of losing business.

A trust is a legal arrangement where multiple companies agree to work together as a single entity to control production, prices, or markets for a particular product or service. This often involves merging their resources and operations, allowing them to eliminate competition and increase profits. Trusts can lead to monopolistic practices, where a small number of companies dominate an entire industry, which can reduce choices and raise prices for consumers.

Interstate commerce is all about trade and business activities that happen between different states in the U.S. This includes things like shipping products from one state to another. The federal government makes sure that this trade is fair and smooth by regulating it, which helps prevent any state from making unfair rules that could hurt businesses in other states.

Irish immigration to the United States was largely driven by the Great Famine (lack of food), which devastated Ireland and led to widespread hunger. Many Irish immigrants settled in urban areas, taking low-wage jobs in factories, construction, and railroads, often facing harsh living conditions and discrimination. Despite these challenges, they formed strong communities that contributed significantly to American culture and labor movements. 

Significant waves of Chinese immigrants arrived in the United States, driven primarily by the search for economic opportunities and the impact of events like the California Gold Rush. Many sought fortune in mining and later contributed to the construction of the Transcontinental Railroad, enduring harsh conditions and discrimination along the way. In 1882, the Chinese Exclusion Act was passed which severely restricted further immigration. 

Many immigrants from Eastern Europe arrived in the United States during this period, seeking economic opportunities or escaping political and religious persecution; among these groups were Greeks, Italians, Poles, Slovaks, Serbs, Russians, Croats, Norwegians, Germans, and others. 

Urbanization in the United States marked a shift from a mostly rural (countryside) society to a more urban (city) one, mainly due to economic changes. As industries grew, factories opened in cities, creating many job opportunities that drew people from rural areas. This migration was driven by the hope for work and available housing in urban settings, leading to a rapid increase in city populations as more individuals sought improved prospects in the expanding industrial landscape. 

Industrialization had a significant impact on cities in the Northeast United States, especially as immigration increased. Cities like New York became the most densely populated in the country, leading to various challenges. Crowded neighborhoods faced serious issues such as disease, poor sanitation, and garbage disposal problems. As cities expanded, previously used farmland was converted into urban areas, resulting in a dramatic rise in the urban population. This rapid growth brought both opportunities and struggles for those living in these crowded environments.

Tenements were apartment buildings where many immigrants and low-income families lived. These buildings were often crowded, with multiple families sharing small, cramped spaces. Living conditions in tenements were typically harsh and unsafe. Many units lacked proper ventilation, heating, and running water, making it difficult to maintain hygiene. Bathrooms were often shared among many families, leading to unsanitary conditions that contributed to the spread of disease. Despite these challenges, tenements provided affordable housing for those seeking better opportunities in the city.

Political corruption was widespread as powerful businessmen and politicians worked together to benefit themselves. Many politicians accepted bribes and offered special privileges to their friends, leading to unfair advantages, like in the case of the "Free Pies Kitchen," where free meals were given to voters in exchange for support. This corruption allowed wealthy individuals to profit while ordinary citizens faced challenges, showing how the government often prioritized the rich over the needs of the people.

Political machines were powerful organizations that controlled local politics during the Gilded Age. One reason they expanded was the rapid influx of immigrants, which made it challenging for local governments to provide basic services. By securing jobs and contracts for their supporters, political machines effectively controlled access to political influence, allowing them to maintain their dominance in urban areas.

Political bosses were influential leaders who controlled political machines in cities. They had significant power by managing local politics, securing votes, and providing services to voters such as making improvements to urban infrastructure in exchange for political support. These bosses typically operated through corrupt practices, such as bribery and favoritism, and they used their control to benefit themselves and their allies, often prioritizing their interests over the needs of the public. Notable examples include Boss Tweed in New York City, who became infamous for his corrupt dealings and manipulation of the political system.