The poem’s guiding metaphor consists of a series of implied similarities between prisoners and immigrants. That comparison is never explicitly stated, but it is suggested in the title and maintained throughout the poem. In fact, a reader with no previous knowledge about the poem or the author might not realize until the third of fourth stanza that the focus is on the experience of prisoners rather than immigrants. The opening description of people with “dreams in our hearts, / looking for better days ahead” (Lines 1-2) could easily apply to immigrants coming to the United States in search of freedom and opportunity. The references to “the gates” and “new papers” (Line 3) support that assumption since they could refer to an immigration checkpoint and a visa. The phrases “the new land” (Line 8) and “the old world” (Line 10) were often used to distinguish between America and Europe in the 19th and early-20th century, when most immigrants came from European countries.

It is that early wave of immigration that the poem evokes. At that time, many immigrants would arrive to an immigration inspection station, most famously on Ellis Island in New York Harbor, where they might be “given shots” and where “doctors [would] ask questions” (Line 6) to prevent infectious diseases being brought into the country.