Vicky,
Yes, you can apply if you were lawfully admitted to the U.S. for at least one year. Your current status is a moot point.
Please read section 5.17 of the CIC Operational Manuals - OP1 Procedures very carefully - "What is meant by lawfully admitted?"
"For the purposes of R11, situations in which an individual is considered to have been “lawfully admitted” will include (but are not limited to):
i) persons who were lawfully admitted, but no longer have legal status when the application is submitted. For example, a person who has entered a country lawfully but at some time subsequent to lawful admission has lost legal immigration status is considered to have been lawfully admitted, whether or not status has been restored at the time of the application to the visa office. Such applicants may or may not qualify for a visa, but their application must be accepted for processing and assessed on its merits;
ii) persons who initially were not lawfully admitted, but have since gained legal status and have legal status at the time an application is submitted"
Good luck!
Source: www . cic.gc.ca/english/resources/manuals/op/op01-eng.pdf (please take out the spaces)