SAN ANTONIO — Hundreds of volunteers plan to keep watch over the area of the Texas-Mexico border around Laredo beginning Sept. 11, and organizers said they’ll offer extra sets of eyes in the U.S. Border Patrol’s effort to stop illegal immigration. The eight-week “Operation Sovereignty” — which begins on the fifth anniversary of the 2001 terrorist attacks and ends on Election Day, Nov. 7 — is meant to “bring national awareness to the illegal alien invasion crisis,” said Minuteman Project founder Jim Gilchrist. Gilchrist, who said he supports legal immigration, said the opening and closing days of the operation are...