The airlines and Customs and Border Protection have certainly noticed a decline in travel.
www.the-independent.com
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Numbers from U.S. Customs and Border Protection (CBP) show that crossings at the northern border fell by 12.5% in February and 18% in March — all amid an atmosphere in which the Trump administration continues to push forward with detentions and deportations at the border while antagonizing Canada with comments about it being the "51st state."
Travel agency Flight Centre Travel Group Canada published a report showing that business travel from Canada fell by 40% in the first months of 2025. The U.S. Travel Association estimated that even a 10% reduction in Canadian tourism would result in the industry losing 140,000 jobs and $2.1 billion (the actual decrease has already been documented as higher).

US airlines forced to cut flights as travel across the country drops
Airlines reported that they would trim its flight schedule for the second half of the year due to lower demand

American Airlines became the latest to withdraw its 2025 financial guidance on Thursday, following similar moves by Southwest and Delta. All three airlines pointed to a decline in bookings from economy leisure travelers as a key factor in the increasingly uncertain economic landscape.

United to cut flights this summer amid economic uncertainty, softer demand
United Airlines is the latest major U.S. carrier to warn that the current economic environment could cut into demand. The carrier said it will trim its domestic capacity starting in the summer.
The Chicago-based carrier [United] said in a regulatory filing on Tuesday that it is cutting domestic capacity by about 4% starting in the third quarter of 2025, "in response to the current demand environment." The airline's third quarter covers July, August and September, traditionally a peak travel period.
Additionally, the carrier announced in its quarterly earnings report that it will also make changes to how often it uses its planes, including flying less on slower travel days, through the end of 2025.