During the decades-long movement to codify the rights of Latinos in the US, certain events were pivotal: the founding of...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

• During the decades-long movement
• to codify the rights of Latinos in the US,
• certain events
• were pivotal:
• the founding of social justice group
• the League of United Latin American Citizens
• in [?]Katzenbach v. Morgan court decision in 1966,
• which affirmed the rights of Latino voters,
• is another such event.
• 
  
• Where [?] represents: 1929[punctuation?]for one[punctuation?][The/the]

Understanding the Meaning

Let's read from the beginning:

"During the decades-long movement to codify the rights of Latinos in the US, certain events were pivotal:"

• The passage is about a long movement to establish Latino rights in the US
• Certain events were pivotal (extremely important) in this movement
• The colon signals that examples are coming

"the founding of social justice group the League of United Latin American Citizens in 1929"

• This is one example of a pivotal event
• The League of United Latin American Citizens was founded in 1929

This is where we have the blank. Let's look at the choices:

• They vary in punctuation after "1929" and "for one"
• They vary in whether "for one" and "The" are capitalized

To see what works here, let's read the rest and understand what it's saying:

"Katzenbach v. Morgan court decision in 1966, which affirmed the rights of Latino voters, is another such event."

• This mentions a different event - a court decision from 1966
• This decision affirmed (supported/confirmed) Latino voting rights
• This IS "another such event" - another pivotal event

Now let's understand what we have structurally:

First part after the colon:

• "the founding of social justice group the League of United Latin American Citizens in 1929"
  • This is a noun phrase - it's describing something
  • But it's NOT a complete sentence on its own
  • There's no verb making a statement about this founding

Second part:

• "Katzenbach v. Morgan court decision in 1966, which affirmed the rights of Latino voters, is another such event"
  • Subject: "Katzenbach v. Morgan court decision in 1966, which affirmed the rights of Latino voters"
  • Verb: "is"
  • This IS a complete sentence - it can stand alone

What do we notice about the structure here?

• We have a noun phrase example (the founding...) followed by a complete sentence (the Katzenbach decision... is another event)
• These are two separate structural units that need proper separation
• The phrase "for one" means "as one example"
  • It makes sense attached to the first example: "the founding... in 1929, for one"
  • This parenthetical expression should be set off by commas
• Then we need to start a new sentence about the other example

So we need: comma before "for one," period after "for one," and capital "The" to start the new sentence

The correct answer is Choice D: "1929, for one. The"

GRAMMAR CONCEPT APPLIED

Separating Complete Sentences from Noun Phrases

When you have a noun phrase (a group of words centered around a noun but without a verb making a complete statement) followed by a complete sentence (subject + verb making a complete thought), you need to separate them properly:

Noun phrase example:

• "the founding of social justice group the League of United Latin American Citizens in 1929, for one"
  • This describes something but doesn't make a complete statement
  • The parenthetical "for one" (set off by commas) adds the meaning "as one example"

Complete sentence:

• "The Katzenbach v. Morgan court decision in 1966, which affirmed the rights of Latino voters, is another such event"
  • Subject: the court decision (with its modifiers)
  • Verb: is
  • This makes a complete statement

The punctuation rule:

• When a complete sentence follows a noun phrase or fragment, use a period to end the first unit and start the new sentence with a capital letter
• Parenthetical expressions like "for one" should be set off by commas

In this question:

• The noun phrase ends: "...in 1929, for one."
• The new sentence begins: "The Katzenbach v. Morgan court decision..."