dont understand why it would take more than 1 year

i hear stories about usc petitoning for spouse and said it took over 1 year.Why would it take this long for a usc.what circumstances would prolong this visa.

i hear stories about usc petitoning for spouse and said it took over 1 year.Why would it take this long for a usc.what circumstances would prolong this visa.

It depends where you filed I-130 and where the beneficiary lives. If a USC applies for spouse it takes about 6 months for its approval and then they will ask for Affidavit of support and other documents before transferring the file to the Consulate abroad.
In case the person is in the United States then it depends on the location where the person resides, because of work load at the INS office.
Good luck