Here are Texas-based (or Texas-focused) agencies that explicitly promote content-driven SEO for law firms, with a short note on each and a source you can check:

1. GrowLaw (Austin) — law‑firm marketing with an emphasis on legal content (blogs, practice pages, FAQs) and local/Austin-focused SEO strategies. (GrowLaw.co)

2. Scale & Sword — positions itself as a Texas law‑firm marketing agency that creates custom legal content (articles, case studies) combined with local SEO. (scaleandsword.com)

3. MojoRhino — Texas-focused solo agency offering content and ebook lead‑magnets plus SEO for small/solo law firms (content-first approach). (MojoRhino.com)

4. Mach 1 Design — Texas digital agency that advertises law‑firm SEO driven by content marketing and case studies for attorneys. (mach1design.com)

5. MileMark Media — provides Texas law‑firm SEO with content, local optimization and link strategies (national reach but lists Texas law firm services). (milemarkmedia.com)

6. LoneStar SEO Pros — Texas SEO agency that highlights law‑firm SEO centered on content and keyword targeting for attorneys. (lonestarseopros.com)

7. 360 Law Firm Marketer — advertises law‑firm content marketing, social and SEO services aimed at Texas firms. (360lawfirmmarketer.com)

8. iLawyer Marketing (Austin) — specializes in attorney SEO and explicitly offers human-written legal content (practice pages, blogs) plus local SEO. (iLawyerMarketing.com)

How to pick among them (quick checklist)

• Ask for case studies showing organic traffic and lead growth for law firms in your practice area and city (content-driven results).
• Confirm who actually writes the legal content (in‑house legal writers vs. general copywriters).
• Request sample content and the content/SEO process (topic research, schema, internal linking, conversion focus).
• Check pricing, exclusivity in your metro/practice area, and reporting cadence.

If you want, I can:

• Narrow this to agencies in a specific Texas city (Houston, Dallas, Austin, San Antonio),
• Pull recent case studies or client references for 2–3 of these agencies, or
• Draft an email template you can send to request proposals and content samples.