Entry laws tightened today for those crossing the US/Canadian or the US/Mexican border on land—now you must have a passport or an acceptable equivalent to get across.

It’s a bit more of a hassle, but at least future genealogists will have records. Plenty of our ancestors immigrated, then up and moved across the border. Some went back and forth several times.

Border-crossing records start later than ship passenger lists. Here’s a rundown of what’s available:

Canada to the United States
Until 1895, border crossings from Canada to the United States weren’t recorded at all. Thereafter, most border crossings are on microfilm known as the St. Albans lists (after the Vermont town where the US Immigration and Naturalization Services had its main office), with geographic coverage varying by year:

• 1895-June 1917: All border crossings
• June 1917-July 1927: Crossings east of the North Dakota/Montana state line
• After July 1927: Crossings east of Lake Ontario

Other 1895-and-later crossings also are microfilmed. The National Archives and Records Administration (NARA) Web site has a handy list of the film. They’re digitized in the subscription site Ancestry.com’s immigration collection, too.

United States to Canada
Ancestors crossing to Canada weren’t recorded until April 1908. Even then, those considered returning Canadians, or who crossed where ports didn’t exist or were closed, weren’t listed. Library and Archives Canada has records; see the Canadian Genealogy Centre for information.

They’re also on Ancestry.ca.

Mexico to the United States
Microfilmed records for ancestors who entered the United States from Mexico—which includes many Asians, Syrians and South Americans, as well as US citizens returning home—start as early as 1903 at some ports. Records begin later for other ports. NARA has an online guide and list of film. These records also are on Ancestry.com.