US border security remains high-priority

It's estimated that more than half a million people try to enter the United States illegally each year.

Since the World Trade Centre attacks on September 11, border security has increased and getting into the country has become more difficult.

The federal government has also increased efforts to locate and deport undocumented immigrants.

In part two of Al Jazeera's special series - Immigration in America, Al Jazeera's Mike Kirsch has this report.