A hobo is a term which is often applied to a migratory worker

Migrant worker

The term migrant worker has different official meanings and connotations in different parts of the world. The United Nations' definition is broad, including any people working outside of their home country...

 or homeless

Homelessness

Homelessness describes the condition of people without a regular dwelling. People who are homeless are unable or unwilling to acquire and maintain regular, safe, and adequate housing, or lack "fixed, regular, and adequate night-time residence." The legal definition of "homeless" varies from country...

 vagabond

Vagabond (person)

A vagabond is a drifter and an itinerant wanderer who roams wherever they please, following the whim of the moment. Vagabonds may lack residence, a job, and even citizenship....

, often penniless

Poverty in the United States

Poverty is defined as the state of one who lacks a usual or socially acceptable amount of money or material possessions. According to the U.S. Census Bureau data released Tuesday September 13th, 2011, the nation's poverty rate rose to 15.1% in 2010, up from 14.3% in 2009 and to its highest level...

. The term originated in the Western

Western United States

.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...

—probably Northwestern

Northwestern United States

The Northwestern United States comprise the northwestern states up to the western Great Plains regions of the United States, and consistently include the states of Oregon, Washington, Idaho, Montana, Wyoming, to which part of southeast Alaska is also sometimes included...

—United States during the last decade of the 19th century. Unlike 'tramp

Tramp

A tramp is a long term homeless person who travels from place to place as a vagrant, traditionally walking or hiking all year round. In British English meanwhile a tramp simply refers to a homeless person, usually not a travelling one....

s', who work only when they are forced to, and 'bums

Slacker

The term "slacker" is used to refer to a person who habitually avoids work. Slackers may be regarded as belonging to an antimaterialistic counterculture, though in some cases their behavior may be due to other causes ....

', who do not work at all, 'hobos' are workers who wander.
The origin of the term is unknown. Etymologist Anatoly Liberman

Anatoly Liberman

Anatoly Liberman is a professor in the Department of German, Scandinavian and Dutch at the University of Minnesota, where he teaches courses in linguistics, etymology, and folklore. Liberman is a native of St. Petersburg, Russia. His main graduate works, written under the auspices of the...

 says that the only details certain about its origin is that the word emerged in American English

American English

American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....

 and was first noticed around 1890.