How Did the Immigration and Nationality Act Change U.S. Immigration?

Almost every visa petition, green card application, or naturalization form filed in the United States today traces back to one law: the Immigration and Nationality Act (INA). Passed in 1952 and reshaped dramatically in 1965, the INA is still the statute USCIS cites in nearly every policy memo it issues, including the ones reshaping green card processing in 2026.

This guide answers the questions people actually search for: what the INA is, how it changed who gets to immigrate, what categories it created, and how it's being applied differently right now. If you're trying to understand where your own case fits, this is the context you need before you talk to a lawyer.

What Is the Immigration and Nationality Act?

The INA is the primary federal law governing immigration and citizenship in the United States. It replaced a patchwork of earlier immigration statutes and consolidated them into a single code, codified at Title 8 of the U.S. Code.

Every visa category, deportation ground, and naturalization requirement in use today, from the E-2 investor visa to asylum eligibility, exists because the INA created it or was later amended to include it. When a client works with an immigration lawyer in Houston, the attorney is, in practice, interpreting sections of this one law and the decades of regulations, court decisions, and USCIS policy memos built on top of it.

The INA's core structure includes:

• A numerical limit system that caps how many immigrant visas are issued each year, by category and by country
• A preference system that ranks family and employment petitions by priority
• Grounds of inadmissibility and deportability, the specific reasons someone can be denied entry or removed
• Naturalization requirements under Sections 316 and 312, covering residency, moral character, and civics knowledge

How Did the 1965 Amendments Change Who Could Immigrate?

Before 1965, U.S. immigration law operated on a national origins quota system. Visa numbers were allocated based on the ethnic makeup of the U.S. population as it existed decades earlier, which heavily favored immigrants from Northern and Western Europe and effectively shut out most of Asia, Africa, and Southern and Eastern Europe.

The Immigration and Nationality Act of 1965 eliminated that quota system entirely. It didn't just adjust the numbers, it changed the philosophy of the law.

What the 1965 amendments actually did:

• Abolished national origin, race, and ancestry as a basis for visa allocation
• Introduced a preference system prioritizing family reunification and needed job skills instead of nationality
• Created the first version of the employment-based preference categories still used today (now EB-1 through EB-5)
• Set per-country caps to prevent any single country from dominating the visa pool
• Established the foundation for the modern family-based petition process, including sponsorship by U.S. citizens and lawful permanent residents

This is the single biggest reason immigration to the U.S. looks the way it does today. Countries in Asia, Latin America, and Africa, which sent comparatively few immigrants before 1965, became major sources of U.S. immigration within a decade of the amendments taking effect.

What Immigration Categories Did the INA Create?

The INA didn't just open the door wider, it built the specific pathways people use to walk through it. Most modern visa categories exist because a later amendment added them into the INA's framework.

Family-based categories cover spouses, children, parents, and siblings of U.S. citizens and lawful permanent residents, split between immediate relatives (no annual cap) and preference categories (numerically limited, longer wait times).

Employment-based categories (EB-1 through EB-5) cover everything from extraordinary-ability professionals to investors. This is also where nonimmigrant work visas like H-1B, L-1, and E-2 draw their statutory authority, even though they're temporary rather than immigrant visas.

Humanitarian categories include asylum, refugee status, and Temporary Protected Status, added to the INA through later amendments like the Refugee Act of 1980.

The Diversity Visa Program, created in 1990, allocates a set number of visas annually to countries with historically low rates of immigration to the U.S., a direct descendant of the 1965 push to spread visa access more evenly.

How Is USCIS Applying the INA Differently in 2026?

This is the part most explainer articles on this topic skip entirely, and it's the part that actually matters right now if you have a pending case.

On May 21, 2026, USCIS issued Policy Memorandum PM-602-0199, reinterpreting how it applies INA Section 245, the adjustment of status provision that lets people already in the U.S. apply for a green card without leaving the country. The memo doesn't rewrite the statute. It reframes adjustment of status as an "extraordinary form of relief" rather than the routine alternative to consular processing it has functioned as for decades.

What changed in practice:

• USCIS officers are now directed to scrutinize an applicant's full immigration history before approving adjustment of status, rather than treating it as a near-default option for statutorily eligible applicants
• The memo applies to pending and future Form I-485 filings, not just new cases
• H-1B, L-1, and other dual-intent visa holders with any gaps or inconsistencies in status are facing closer review at the adjustment stage
• The change runs alongside two other 2026 developments built on INA authority: reactivated mandatory alien registration requirements and continued enforcement tied to the Laken Riley Act

None of this changes what the INA says. It changes how the agency is choosing to exercise the discretion the INA already gave it. That distinction is exactly why case strategy in 2026 needs a lawyer who tracks USCIS policy memos, not just the underlying statute.

Does the INA Still Apply the Same Way to Business and Investor Visas?

Yes, but the practical risk has shifted. The E-2 treaty investor visa, the H-1B specialty occupation visa, and the L-1 intracompany transfer visa are all nonimmigrant classifications created under INA Section 101(a)(15), and none of those statutory definitions changed in 2026. What changed is what happens after someone on one of those visas tries to adjust to permanent residence.

An E2 visa attorney who understands both the investment requirements under INA Section 101(a)(15)(E) and the current adjustment of status climate can help structure a case, and a transition to a green card path, in a way that anticipates this closer scrutiny instead of getting caught by it. For anyone weighing an E-2 investment against an eventual green card strategy, this is no longer a detail to leave until later in the process.

Why Work With an Immigration Lawyer in Houston Right Now?

The INA is over 70 years old and has been amended dozens of times, but the statute itself rarely changes as fast as the policy memos interpreting it do. That gap between the law on paper and the law as USCIS is enforcing it this year is exactly where cases get delayed, or denied.

If you're evaluating a petition, a pending adjustment of status application, or a visa renewal, it's worth reviewing our essential questions to ask an immigration lawyer in Houston before your first consultation, so you walk in prepared.

Key Takeaway

The Immigration and Nationality Act replaced a discriminatory quota system with the family- and employment-based framework still in use today, and every visa category from family green cards to E-2 investor status exists because of it. But 2026 is a reminder that the statute is only half the picture. How USCIS chooses to apply that statute, especially around adjustment of status, is changing in real time.

If you have a pending case, or you're planning one, don't rely on outdated assumptions about how the process works. Salinas Law Firm has represented clients before USCIS and U.S. Consulates for more than 19 years, through exactly this kind of policy shift. Call 713.518.1711 or schedule a consultation to talk through where your case stands.